Chemical Reactivity Flashcards
1
Q
What is the soul of chemistry?
A
Chemical reactions.
2
Q
Why does sodium catch fire in air but gold and platinum do not?
A
Sodium is highly reactive, while gold and platinum are very unreactive.
3
Q
How are metals found in nature?
A
Some are found free, while others exist in combined states as compounds.
4
Q
What are the key properties of metals?
A
Good conductors of heat/electricity, malleable, ductile, and form basic oxides/hydroxides.
5
Q
Which metal is liquid at room temperature?
A
Mercury (Hg).
6
Q
How do metals react with oxygen and water?
A
They form basic oxides; when dissolved in water, they form alkaline solutions that turn red litmus blue.
7
Q
How are metals defined in terms of electrons?
A
Metals lose electrons to form cations (positively charged ions).
8
Q
Give an example of a metal losing electrons.
A
Sodium (Na) loses one electron to form Na⁺.
9
Q
What is the exception to metals being electron donors?
A
Hydrogen (H), which can also donate electrons.
10
Q
Which group in the periodic table contains all metals except Hydrogen?
A
Group 1.
11
Q
Which group contains all metals?
A
Group 2.
12
Q
Which group contains only Boron as a non-metal?
A
Group 3.
13
Q
Which two metals are in Group 4?
A
Tin (Sn) and Lead (Pb).
14
Q
Which metals are in Group 5?
A
Antimony (Sb) and Bismuth (Bi).
15
Q
Which groups contain only non-metals?
A
Groups 6, 7, and 8.
16
Q
What type of elements are in the d-block?
A
All are metals.
17
Q
What type of elements are lanthanides and actinides?
A
All are metals.
18
Q
What percentage of the Earth is made up of aluminum?
A
About 8%.
19
Q
What percentage of the Earth is made up of iron?
A
5%
20
Q
What percentage of the Earth is made up of calcium?
A
4%
21
Q
Which elements make up less than 4% of the Earth?
A
Potassium, sodium, and magnesium.
22
Q
What is electropositive or metallic character?
A
The tendency of an element to lose electrons and form positive ions (cations).
23
Q
Which elements have more metallic character?
A
Elements with lower ionization energy.
24
Q
Why do alkali metals have high electropositive character?
A
They have very low ionization energies and lose electrons easily.
25
What is the relationship between ionization energy and metallic character?
Lower ionization energy = higher metallic character.
26
Which group of elements are the most electropositive?
Alkali metals.
27
How do non-metals form anions?
They accept electrons in their valence shell.
28
What happens to metallic character across a period (left to right)?
Metallic character decreases.
29
What happens to non-metallic character across a period (left to right)?
Non-metallic character increases.
30
What trend does atomic number follow in relation to metallic and non-metallic character?
As atomic number increases across a period, metallic character decreases and non-metallic character increases.
31
Are metals good conductors of electricity?
Yes, metals are good conductors.
32
Are non-metals good conductors of electricity?
No, non-metals are insulators except for graphite (carbon).
33
How is the electrolysis test used to determine if an element is metallic?
The element is dissolved in acid, and an electric current is passed through. If metallic, its atoms become positively charged and move toward the cathode.
34
What is an example of an electrolysis reaction with zinc?
Zn + 2HCl → ZnCl₂ + H₂
ZnCl₂ → Zn+² + 2Cl-¹
35
What are alkali metals?
Elements in Group 1A (except Hydrogen).
36
Why are they called alkali metals?
Their name comes from the Arabic word for "ashes" because they were first found in plant ashes.
37
Name all alkali Metals?
Lithium (Li), Sodium (Na), Potassium (K), Rubidium (Rb), Cesium (Cs), Francium (Fr).
38
How many valence electrons do alkali metals have?
One valence electron.
39
What is the valence sub-shell of alkali metals?
"s" sub-shell.
40
Why are alkali metals highly electropositive?
They lose one electron easily to form mono-positive ions.
41
Do alkali metals have high or low ionization energy?
Low ionization energy.
42
What happens to the electron lost by alkali metals?
It is transferred to an electronegative element to form ionic compounds.
43
With which groups do alkali metals form ionic compounds?
Group VI and Group VII.
44
Why do alkali metals not occur in the free state?
They have low ionization energies and are very reactive.
45
How does lithium occur in nature?
In the form of complex minerals like Spodumene (LiAl(SiO₃)₂).
46
In what quantity are sodium and potassium found in earth crust?
Abundantly in the Earth's crust.
47
Where are rubidium and cesium found?
In small amounts in potassium salt deposits.
48
Is francium found in nature?
No, francium is not found in nature; it is prepared in the laboratory.
49
Which alkali metal is the rarest in nature?
Francium.
50
Which alkali metals are most abundant on Earth?
Sodium and potassium.
51
Which elements in Period 2 are metals?
Lithium (Li) and Beryllium (Be).
52
Which element in Period 2 is a metalloid?
Boron (B).
53
Which elements in Period 2 are non-metals?
Carbon (C), Nitrogen (N), Oxygen (O), Fluorine (F), and Neon (Ne).
54
Which elements in Period 3 are metals?
Sodium (Na), Magnesium (Mg), and Aluminum (Al).
55
Which element in Period 3 is a metalloid?
Silicon (Si).
56
Which elements in Period 3 are non-metals?
Phosphorus (P), Sulfur (S), Chlorine (Cl), and Argon (Ar).
57
What happens to metallic character as you go down a group?
It increases from top to bottom.
58
What happens to metallic character across a period (left to right)?
Metallic character decreases.
59
What happens to non-metallic character across a period (left to right)?
Non-metallic character increases.
60
Which elements in Group IV are non-metals?
Carbon (C).
61
Which elements in Group IV are metalloids?
Silicon (Si) and Germanium (Ge).
62
Which elements in Group IV are metals?
Tin (Sn) and Lead (Pb).
63
Which elements in Group V are non-metals?
Nitrogen (N) and Phosphorus (P).
64
Which elements in Group V are metalloids?
Arsenic (As) and Antimony (Sb).
65
Which element in Group V is a metal?
Bismuth (Bi).
66
What is the order of reactivity of alkali metals (lithium, sodium and potassium)?
Lithium < Sodium < Potassium.
67
How does lithium react with air (oxygen)?
Lithium burns with a red flame to give lithium oxide (Li₂O), a white solid.
68
How does sodium react with air (oxygen)?
Sodium burns with a bright yellow flame to produce sodium oxide (Na₂O).
69
How does potassium react with air (oxygen)?
Potassium burns with a lilac flame to produce potassium oxide (K₂O).
70
How does lithium react with water?
Lithium floats on water and reacts quickly to produce lithium hydroxide (LiOH) and hydrogen gas (H₂).
71
How does sodium react with water?
Sodium floats on water and reacts quickly to produce sodium hydroxide (NaOH) and hydrogen gas (H₂).
72
How does potassium react with water?
Potassium floats on water and reacts very violently (explodes) to produce potassium hydroxide (KOH) and hydrogen gas (H₂).
73
What is the reaction of lithium with chlorine?
Lithium burns with a bright flame to form lithium chloride (LiCl), a white solid.
74
What is the reaction of sodium with chlorine?
Sodium burns with a bright flame to form sodium chloride (NaCl), a white solid.
75
What is the reaction of potassium with chlorine?
Potassium burns with a bright flame to form potassium chloride (KCl), a white solid.
76
What are alkaline earth metals?
Elements in Group IIA of the periodic table that produce alkalies and are widely distributed in the Earth's crust.
77
How many electrons do alkaline earth metals have in their valence shells?
Two electrons.
78
What is the valence sub-shell of alkaline earth metals?
"s" sub-shell.
79
How do alkaline earth metals become
stable?
By losing their two valence electrons to form M²⁺ ions and attaining the electron configuration of noble gases.
80
What is the ionization energy of alkaline earth metals?
Low ionization energies.
81
What are some examples of alkaline earth metals?
Beryllium (Be), Magnesium (Mg), Calcium (Ca), Strontium (Sr), Barium (Ba), and Radium (Ra).
82
In what form are alkaline earth metals often found in nature?
In the form of sulfates.
83
What are some examples of minerals containing alkaline earth metals?
Gypsum (calcium sulfate), Epsom (magnesium sulfate), and Barite (barium sulfate).
84
Explain reactivity of alkaline earth metals and their reason?
Alkaline earth metals are very reactive due to their low ionization energies, so they do not occur free in nature.
85
Where is Beryllium found in nature?
Beryllium occurs in nature in small amounts in the form of Beryl.
86
Are Magnesium and Calcium abundant in nature or rare?
Magnesium and Calcium are very abundant in the Earth's crust.
87
How are Magnesium and Calcium found in nature?
Magnesium and Calcium are present with Sodium and Potassium as cations in rocks.
88
Where are Magnesium halides found?
In seawater.
89
What is an important function of Magnesium?
Magnesium is an important constituent of Chlorophyll.
90
In what compound form is Calcium found in nature?
Calcium is found in nature in the form of Calcium phosphate and Calcium Fluoride.
91
What is the importance of Calcium in living organisms?
Calcium is an important constituent of skeletal materials in bones, teeth, and eggshells.
92
What is Radium?
Radium is a rare, radioactive element.
93
What is ionization energy?
The minimum energy required to remove the valence electron from the outermost shell of a gaseous atom to form a positive ion.
94
How is ionization energy measured?
Ionization energy is measured in joules or kilojoules per mole.
95
How does ionization energy compare between Alkali and Alkaline Earth metals?
Alkali metals have lower ionization energies and are more reactive than Alkaline Earth metals.
96
What makes alkali metals highly reactive?
Alkali metals have one electron in their outermost shell, which is easily removed, making them the most reactive metals.
97
What is the ionization energy of Sodium (Na)?
496 kJ/mole.
98
Why does lithium have the highest ionization energy in Alkali metals?
Lithium is at the top of the group with the smallest atomic size and the shortest distance between the nucleus and the valence shell.
99
How does atomic size affect ionization energy?
As atomic size increases (down the group), ionization energy decreases because the valence electron is less firmly held by the nucleus.
100
What type of Ionization energies do Alkali Metals (Group I) have?
Alkali metals have low ionization energies that decrease down the group:
101
Atomic radius trend in Alkali Metals (Group I)
Atomic radius increases down the group due to increasing electron shells:
102
What are Alkali Metals?
Alkali metals are Group I elements that have one valence electron and are highly reactive.
103
What is the trend of ionization energy in Alkali Metals (Group I)?
Ionization energy decreases down the group:
104
What is the trend of atomic radius in Alkali Metals (Group I)?
Atomic radius increases down the group due to additional electron shells:
105
What are Alkaline Earth Metals?
Alkaline Earth Metals are Group IIA elements with two valence electrons. They are the second most electropositive metals.
106
How do Alkaline Earth Metals compare to Alkali Metals?
Have two valence electrons instead of one. Higher ionization ,energy. Smaller atomic radius due to stronger nuclear attraction, Higher melting and boiling points, Harder and denser than alkali metals.
107
Why do Alkaline Earth Metals form M²⁺ cations?
They lose two valence electrons to achieve a stable electron configuration, forming **M²⁺** ions.
108
Why do Alkaline Earth Metals have a smaller atomic radius than Alkali Metals?
They have a higher nuclear charge, pulling electrons closer to the nucleus, resulting in a smaller atomic radius.
109
Why do Alkaline Earth Metals have higher ionization energy than Alkali Metals?
Their second valence electron is in the same sublevel as the first, requiring more energy to remove due to stronger nuclear attraction.
110
Why is it harder to remove a second electron from an ion?
More energy is needed because the nuclear attraction increases.
111
Ionization energy of Mg⁺ and Mg²⁺
Mg⁺ : 737.7kj/mol
Mg²⁺ : 1450.7 kJ/mol.
112
Why does Beryllium have the highest ionization energy in Group II?
Beryllium is at the top of the group and has a small size.
113
What happens to ionization energy as you go down Group II?
It decreases because atomic size increases.
114
Why are Alkali Metals more reactive than Alkaline Earth Metals?
Alkali metals have lower ionization energy, making ion formation easier.
115
What happens to melting points and hardness from Alkali to Alkaline Earth Metals?
They increase.
116
What happens to atomic radii and conductivity from Alkali to Alkaline Earth Metals?
They decrease.
117
Why isn’t sodium found as a free metal?
It is too reactive.
118
Where is sodium found?
It is found in the sea as sodium chloride sodium bromide and sodium iodide. It is also found in deposits as rock salt.
119
What happens when alkali metals are cut?
They shine but quickly tarnish.
120
Where is sodium in the periodic table?
Group 1, Period 3, atomic number 11.
121
What is the symbol of sodium?
Na.
122
How many valence electrons does sodium have?
One.
123
Why does sodium belong to Group 1?
It has one valence electron.
124
Why does sodium belong to Period 3?
It has three electron shells.
125
What is the main compound of sodium in seawater?
Sodium chloride (NaCl).
126
What other sodium compounds are found in nature?
Sodium bromide (NaBr) and sodium iodide (NaI).
127
What is the trend in electropositivity from Alkali to Alkaline Earth Metals?
It decreases.
128
What is the trend in reducing power from Alkali to Alkaline Earth Metals?
It decreases.
129
What is the trend in density from Alkali to Alkaline Earth Metals?
It increases.
130
What is the trend in reactivity in Alkali Metals?
It increases down the group.
131
What is the appearance of freshly cut sodium?
Shiny and silvery.
132
Why does sodium quickly tarnish in air?
It reacts with oxygen and moisture.
133
What is the appearance of sodium?
Silvery white solid.
134
Is sodium hard or soft?
Soft, can be cut with a knife.
135
What is the density of sodium?
0.971 g\cm³ (it is lighter than water and it floats on the surface of water)
136
What is the melting point of sodium?
97.6°C.
137
What is the boiling point of sodium?
880°C.
138
Is sodium strong?
No, it has low tensile strength.
139
Is sodium malleable and ductile?
Yes.
140
Is sodium a good conductor?
Yes, it conducts heat and electricity well.
141
Why is sodium highly reactive?
It is an alkali metal and a strong reducing agent.
142
What happens when sodium reacts with hydrogen?
It forms sodium hydride (NaH).
2Na + H2 -------> 2NaH
143
What happens when sodium reacts with oxygen?
It forms basic sodium oxide (2Na₂O). Which on reaction with water forms alkali (NaOH)
144
What does sodium oxide form when it reacts with water?
Sodium hydroxide (NaOH).
145
Why are Group 1 elements called alkali metals?
They form strong bases (alkalis) when reacting with water.
146
What happens when sodium reacts with water?
It reacts vigorously, producing hydrogen gas and heat. It is an exothermic reaction
147
Why does sodium catch fire in water?
The reaction is exothermic, and the heat ignites the hydrogen gas.
148
Reaction of sodium with hydrogen?
2Na + H₂ → 2NaH
149
Reaction of sodium with oxygen?
4Na + O₂ → 2Na₂O
150
Reaction of sodium with water?
2Na + 2H₂O → 2NaOH + H₂ + heat
151
Why is sodium kept in kerosene or liquid paraffin?
To prevent contact with air, oxygen, and water due to high reactivity.
152
What happens when sodium reacts with halogens?
It forms sodium halides.
153
Reaction of sodium with chlorine?
2Na + Cl₂ → 2NaCl
154
Reaction of sodium with bromine?
2Na + Br₂ → 2NaBr
155
What happens when sodium reacts with sulfur?
It forms sodium sulfide (Na₂S).
156
Reaction of sodium with sulfur?
2Na + S → Na₂S
157
Why is sodium a strong reducing agent?
It reduces most oxides and halides.
158
Reaction of sodium as a reducing agent with MgO and TiCl?
2Na + MgO → Na₂O + Mg
4Na + TiCl₄ → 4NaCl + Ti
159
What agent is sodium?
It is a powerful reducing agent.
160
How is sodium used in nuclear reactors?
It is used as a coolant.
161
Which important compounds are made using sodium?
Sodium carbonate (Na₂CO₃), sodium bicarbonate (NaHCO₃), sodium hydroxide (NaOH), sodamide (NaNH₂).
162
How is sodium used in street lighting?
It is used in sodium vapor lamps for bright orange-yellow light.
163
How is sodium used in petroleum purification?
It removes sulfur (desulfurization).
164
How is sodium used in metal extraction?
It helps extract metals like titanium and zirconium from their chlorides and oxides.
165
What alloys does sodium form?
Sodium forms alloys like sodium amalgam (with mercury) and alloys with silver.
166
What type of metal is magnesium (group)?
An alkaline earth metal.
167
In what form does magnesium occur in nature?
Only in a combined state.
168
Name some natural sources of magnesium.
Dolomite (CaCO₃·MgCO₃), Kieserite (MgSO₄), Epsom salt (MgSO₄·7H₂O).
169
Where is magnesium found in seawater?
As chlorides and bromides.
170
What is magnesium responsible for in water?
Permanent hardness.
171
What is magnesium's role in plants?
It is an essential part of chlorophyll.
172
What is the atomic number of magnesium?
12
173
What is the symbol of magnesium?
Mg.
174
Where is magnesium in the periodic table?
Group IIA, Period 3.
175
How many valence electrons does magnesium have?
Two.
176
What is the appearance of magnesium?
Silvery grey solid.
177
What is the density of magnesium?
1.74 g/cm³.
178
What is the melting point of magnesium?
651°C.
179
What is the boiling point of magnesium?
1106°C.
180
Is magnesium malleable and ductile?
Yes.
181
Is magnesium a good conductor?
Yes, it conducts heat and electricity well.
182
Why doesn’t calcium occur as a free metal?
It is too reactive.
183
Where is calcium found in nature?
In minerals like limestone, marble, chalk, and gypsum.
184
What is the chemical formula of calcium carbonate?
CaCO₃.
185
What is the chemical formula of calcium sulfate?
CaSO₄.
186
What is the atomic number of calcium?
20
187
What is the symbol of calcium?
Ca.
188
Where is calcium in the periodic table?
Group IIA, Period 4.
189
How many valence electrons does calcium have?
Two.
190
What is the appearance of calcium?
Silvery white solid.
191
What is the density of calcium?
1.55 g/cm³.
192
What is the melting point of calcium?
851°C.
193
What is the boiling point of calcium?
1487°C.
194
Is calcium malleable and ductile?
Yes.
195
Is calcium a good conductor?
Yes, it conducts heat and electricity well.
196
What happens when magnesium and calcium react with hydrogen?
They form hydrides.
197
Reaction of magnesium with hydrogen?
Mg + H₂ → MgH₂.
198
Reaction of calcium with hydrogen?
Ca + H₂ → CaH₂.
199
What happens when magnesium and calcium burn in air?
They form oxides.
200
Reaction of magnesium with oxygen?
2Mg + O₂ → 2MgO.
201
Reaction of calcium with oxygen?
2Ca + O₂ → 2CaO.
202
What is the common name of magnesium oxide (MgO)?
Magnesia.
203
What color flame does calcium produce when burning?
Brick red.
204
What happens when magnesium oxide (MgO) and calcium oxide (CaO) dissolve in water?
They form basic solutions.
205
Reaction of magnesium oxide with water?
MgO + H₂O → 2Mg(OH)₂.
206
Reaction of calcium oxide with water?
CaO + H₂O → 2Ca(OH)₂.
207
What happens when magnesium and calcium react with nitrogen?
They form nitrides.
208
Reaction of magnesium with nitrogen?
3Mg + N₂ → Mg₃N₂.
209
Reaction of calcium with nitrogen?
3Ca + N₂ → Ca₃N₂.
210
What happens when magnesium and calcium react with acids?
They liberate hydrogen gas.
211
Reaction of magnesium with hydrochloric acid?
Mg + 2HCl → MgCl₂ + H₂.
212
Reaction of magnesium with sulfuric acid?
Mg + H₂SO₄ → MgSO₄ + H₂.
213
Reaction of calcium with hydrochloric acid?
Ca + 2HCl → CaCl₂ + H₂.
214
Reaction of calcium with sulfuric acid?
Ca + H₂SO₄ → CaSO₄ + H₂.
215
What happens when magnesium and calcium react with halogens?
They form halides.
216
Reaction of magnesium with chlorine?
Mg + Cl₂ → MgCl₂.
217
Reaction of magnesium with bromine?
Mg + Br₂ → MgBr₂.
218
Reaction of calcium with chlorine?
Ca + Cl₂ → CaCl₂.
219
Reaction of calcium with bromine?
Ca + Br₂ → CaBr₂.
220
Why is magnesium used in alloys?|It is a low-density metal
making alloys light but strong.
221
What are some magnesium alloys and their uses?|Duralumin (Al
Cu
222
How is magnesium used in photography and fireworks?|It is used in flashlight powder
flames
223
How is magnesium used in metallurgy?.
|It acts as a deoxidant and is used in titanium and uranium extraction
224
How is magnesium oxide (MgO) used in construction?
|It is mixed with clay to make refractory bricks for furnace linings.
225
What industries use magnesium sulfate (MgSO₄)?
Textile, paper, soap and pharmaceutical
226
How is calcium used in metallurgy?
|It acts as a deoxidant in steel castings and copper alloys.
227
What compounds of calcium are used in industries?
|Calcium fluoride ,calcium hydride
228
How is lime (CaO) used in agriculture?
|It is added to soil to reduce acidity.
229
How is calcium used in water treatment and manufacturing?|It is used for water softening
pollution control
230
How is calcium used in steel production?
|It is used in the steel-making process.
231
What are soft metals?|Metals in Group I and II that are very reactive
have low ionization energies
232
What are hard metals?|Metals like copper
silver
233
How do hard metals compare to soft metals?|They have higher melting points
boiling points
234
What is the atomic number of sodium (Na)?
11
235
What is the atomic number of iron (Fe)?
26
236
How many electrons does sodium have in its outer shell?
One.
237
What is the texture of sodium?
It is soft and can be cut with a knife.
238
What is the texture of iron?
It is hard and requires great energy to break.
239
What is the melting point of sodium?
97.6°C.
240
What is the melting point of iron?
1538°C.
241
What is the boiling point of sodium?
880°C.
242
What is the boiling point of iron?
2862°C.
243
What is the density of sodium?
0.927 g/cm³.
244
What is the density of iron?
7.874 g/cm³.
245
Does sodium float on water?
Yes, it is lighter and floats on the surface.
246
Does iron float on water?
No, it is heavy and settles at the bottom.
247
What is the tensile strength of sodium?
Low, it cannot be used in construction.
248
What is the tensile strength of iron?
High, it is used in construction of buildings and bridges.
249
How reactive is sodium?
Very reactive, it is stored in kerosene oil.
250
How reactive is iron?
Less reactive than sodium.
251
Why are transition metals less reactive?
They have high ionization energies.
252
What are noble metals?
Metals that resist oxidation and corrosion in moist air.
253
Give examples of noble metals?
Ruthenium (Ru), rhodium (Rh), palladium (Pd), silver (Ag), osmium (Os), iridium (Ir), platinum (Pt), and gold (Au).
254
What other metals are sometimes considered noble metals?
Mercury (Hg), rhenium (Re), and copper (Cu).
255
Why are noble metals valuable?
Because of their inertness, rarity, and usefulness in areas like metallurgy, high technology, and jewelry.
256
What is the atomic number of sodium (Na)?
11
257
What is the atomic number of iron (Fe)?
26
258
How many electrons does sodium have in its outer shell?
One.
259
What is the texture of sodium?
It is soft and can be cut with a knife.
260
What is the texture of iron?
It is hard and requires great energy to break.
261
What is the melting point of sodium?
97.6°C.
262
What is the melting point of iron?
1538°C.
263
What is the boiling point of sodium?
880°C.
264
What is the boiling point of iron?
2862°C.
265
What is the density of sodium?
0.927 g/cm³.
266
What is the density of iron?
7.874 g/cm³.
267
Does sodium float on water?
Yes, it is lighter and floats on the surface.
268
Does iron float on water?
No, it is heavy and settles at the bottom.
269
What is the tensile strength of sodium?
Low, it cannot be used in construction.
270
What is the tensile strength of iron?
High, it is used in construction of buildings and bridges.
271
How reactive is sodium?
Very reactive, it is stored in kerosene oil.
272
How reactive is iron?
Less reactive than sodium.
273
Why are transition metals less reactive?
They have high ionization energies.
274
What are noble metals?
Metals that resist oxidation and corrosion in moist air.
275
Give examples of noble metals?
Ruthenium (Ru), rhodium (Rh), palladium (Pd), silver (Ag), osmium (Os), iridium (Ir), platinum (Pt), and gold (Au).
276
What other metals are sometimes considered noble metals?
Mercury (Hg), rhenium (Re), and copper (Cu).
277
Why are noble metals valuable?
Because of their inertness, rarity, and usefulness in areas like metallurgy, high technology, and jewelry.
278
What is the atomic number of sodium (Na)?
11
279
What is the atomic number of iron (Fe)?
26
280
How many electrons does sodium have in its outer shell?
One.
281
What is the texture of sodium?
It is soft and can be cut with a knife.
282
What is the texture of iron?
It is hard and requires great energy to break.
283
What is the melting point of sodium?
97.6°C.
284
What is the melting point of iron?
1538°C.
285
What is the boiling point of sodium?
880°C.
286
What is the boiling point of iron?
2862°C.
287
What is the density of sodium?
0.927 g/cm³.
288
What is the density of iron?
7.874 g/cm³.
289
Does sodium float on water?
Yes, it is lighter and floats on the surface.
290
Does iron float on water?
No, it is heavy and settles at the bottom.
291
What is the tensile strength of sodium?
Low, it cannot be used in construction.
292
What is the tensile strength of iron?
High, it is used in construction of buildings and bridges.
293
How reactive is sodium?
Very reactive, it is stored in kerosene oil.
294
How reactive is iron?
Less reactive than sodium.
295
Why are transition metals less reactive?
They have high ionization energies.
296
What are noble metals?
Metals that resist oxidation and corrosion in moist air.
297
Give examples of noble metals?
Ruthenium (Ru), rhodium (Rh), palladium (Pd), silver (Ag), osmium (Os), iridium (Ir), platinum (Pt), and gold (Au).
298
What other metals are sometimes considered noble metals?
Mercury (Hg), rhenium (Re), and copper (Cu).
299
Why are noble metals valuable?
Because of their inertness, rarity, and usefulness in areas like metallurgy, high technology, and jewelry.
300
What are noble metals?
Metals that resist oxidation and corrosion in moist air.
301
Give examples of noble metals.
Ruthenium (Ru)
302
What are precious metals?
Expensive metals with great commercial and economic value.
303
Which noble metals are considered precious metals?
Silver (Ag)
304
What is the color of silver?
It is a soft
305
How does silver occur in nature?
As an element
306
Why is silver valuable?
It is rare and has high economic value due to its physical properties.
307
Is pure silver soft?
Yes
308
Why is silver mixed with copper?
To form an alloy for making commercial articles like coins
309
What is silver chloride used for?
It is used in photography.
310
What are some uses of silver?
It is used for coins
311
Why is platinum expensive?
It is the 72nd most common element in Earth's crust.
312
What does the name "platinum" mean?
It comes from the Spanish word "platina
313
What are the properties of platinum?
Heavy
314
Why is platinum considered a noble metal?
It is unreactive
315
What is platinum used for?
In catalytic converters
316
Why is platinum used in jewelry?
Its ease of shaping
317
What are the uses of platinum outside of jewelry?
Used in the electrical industry
318
What are the special properties of gold?
Very high luster
319
Why is pure gold alloyed with other metals?
To increase durability as pure gold is too soft for most jewelry.
320
What were gold coins used for?
Gold coins were commonly used in transactions before paper currency became more common.
321
Why is gold used in computers?
Because it is an excellent conductor
322
What are gold alloys used for?
Dental fillings
323
Why is gold used in dentistry?
Because it is chemically inert
324
What are non-metals?
Substances that do not conduct heat or electricity
325
What happens when non-metals burn in oxygen?
They produce an oxide that is usually acidic.
326
What happens when non-metal oxides dissolve in water?
They form an acidic solution that turns blue litmus paper red.
327
What is the electron behavior of metals?
Metals are electron donors during chemical reactions and act as reducing agents.
328
What happens to metals in solutions?
Metals become positively charged ions in solutions.
329
What kind of oxide do metals form?
Metals form basic oxides
330
What type of chlorides do metals form?
Metals form electrovalent (ionic) chlorides.
331
Can metals combine with hydrogen?
Metals do not combine easily with hydrogen. Few hydrides formed are electrovalent.
332
What state are metals usually in at room temperature?
Metals are usually solids at room temperature (except mercury).
333
What are metals good at?
Metals are good conductors of heat and electricity.
334
How do non-metals behave in chemical reactions?
Non-metals are electron acceptors and act as oxidizing agents during chemical reactions.
335
What happens to non-metals in solutions?
Non-metals become negatively charged ions in solutions.
336
What type of oxide do non-metals form?
Non-metals form mainly acidic oxides
337
What type of chlorides do non-metals form?
Non-metals form covalent chlorides.
338
How do non-metals react with hydrogen?
Non-metals combine easily with hydrogen to form many stable covalent hydrides.
339
What state are non-metals usually in at room temperature?
Non-metals are often gases at room temperature (except Br2
340
What are non-metals poor at?
Non-metals are poor conductors of heat and electricity (except graphite).
341
What is electronegativity?
Electronegativity is the ability of an atom to attract the shared pair of electrons in a covalent bond.
342
Where are the most electronegative elements found?
The most electronegative elements are found at the right corner of the periodic table
343
What are halogens?
Halogens are elements in Group VII of the periodic table
344
What does the word "halogen" mean?
The word "halogen" comes from the Greek word meaning "salt-forming."
345
Why do halogens not exist in elemental form in nature?
Halogens are highly reactive
346
What is the state of halogens at room temperature?
Fluorine and chlorine are gases
347
How does the reactivity of halogens vary?
Reactivity decreases from fluorine to astatine. Fluorine is the most reactive
348
What is the electronic configuration of halogens?
The electronic configuration of halogens is ns²np⁵. They need one electron to complete their octet.
349
What happens when halogens gain an electron?
When halogens gain an electron
350
What is an example of a halide ion?
An example of a halide ion is the chloride ion (Cl⁻)
351
What physical states do halogens exist in at standard temperature and pressure?
Halogens exist in all three states of matter at standard temperature and pressure: solid (iodine
352
Are halogens good conductors of heat and electricity?
No
353
What are some physical properties of halogens?
Halogens have low melting and boiling points
354
What are the atomic radii of halogens?
The atomic radii of halogens increase from fluorine to astatine (71 pm for fluorine
355
What is the electronegativity trend of halogens?
The electronegativity of halogens decreases as you move from fluorine to astatine (fluorine has 4.0
356
What is the chemical reactivity of halogens?
Halogens are highly reactive
357
How do halogens exist in nature?
Halogens typically exist in a diatomic state (e.g.
358
What are some reactions of halogens?
Halogens react with hydrogen
359
How do halogens react with hydrogen?
Halogens react with hydrogen to form hydrogen halides. For example
360
How do halogens react with oxygen?
Fluorine reacts with oxygen to form fluorine monoxide (FO) and fluorine dioxide (FO₂)
361
How do halogens react with metals?
Halogens react with metals to form ionic halides. The ionic character decreases as you move down the group (fluorine to iodine).
362
What are the reactions of halogens with non-metals?
Halogens react with non-metals to form covalent halides. For example
363
What are the properties of halogen hydrides?
Halogen hydrides act as strong reducing agents and exhibit hydrogen bonding in their structures. Fluorine is especially reactive.
364
What is a non-metal based on electron gain and loss?
A non-metal gains electrons to form anions.
365
Why are non-metals electronegative?
They have a tendency to gain electrons.
366
What are noble metals?
Rare metals with high durability and economic value
367
What are some uses of noble metals?
Jewelry
368
Which metals are included in the platinum group?
Rhenium
369
What makes noble metals unique chemically?
They are less reactive than most metals.
370
Which metals have historically been used for coins and jewelry?
Copper
371
Why is copper a common coinage metal?
It has high luster and malleability.
372
What is Cu-Ni alloy used for?
Making coins.
373
Which elements are non-metals?
Hydrogen
374
Which non-metals are gases at room temperature?
Argon
375
Which non-metal is a liquid at room temperature?
Bromine (Br).
376
Which non-metals are solids?
Carbon
377
Which metals are liquid at room temperature?
Mercury (Hg)
378
What is the melting point of Mercury (Hg)?
38.87°C.
379
What is the melting point of Gallium (Ga)?
29.76°C.
380
What is the melting point of Cesium (Cs)?
28.4°C.
381
What happens when chlorine reacts with lime water (Ca(OH)₂)?
Chlorine reacts with lime water to form bleaching powder (CaOCl₂).
382
What is the order of halogen reactivity?
F > Cl > Br > I > At
383
What happens when a more reactive halogen reacts with a halide solution of a less reactive halogen?
The more reactive halogen displaces the less reactive halogen from its halide solution.
384
How does oxidation power change down the halogen group?
Oxidation power decreases down the group as the size of halogens increases.
385
Write the reaction equation for phosphorus reacting with chlorine gas.
2P(s) + 3Cl₂(g) → 2PCl₃(aq)
386
Write the reaction equation for phosphorus reacting with bromine.
2P(s) + 3Br₂(l) → 2PBr₃(aq)
387
Write the reaction equation for phosphorus reacting with excess chlorine.
2P(s) + 5Cl₂(g) → 2PCl₅(aq)
388
Write the reaction equation for phosphorus reacting with excess bromine.
2P(s) + 5Br₂(l) → 2PBr₅(aq)
389
Write the reaction equation for chlorine reacting with hydrogen sulfide.
H₂S(aq) + Cl₂(g) → 2HCl(aq) + S(s)
390
Write the reaction equation for ammonia reacting with chlorine.
2NH₃(aq) + 3Cl₂(g) → 6HCl(aq) + N₂(g)
391
Write the reaction equation for sodium reacting with bromine.
2Na(s) + Br₂(l) → 2NaBr(aq)
392
Write the reaction equation for calcium hydroxide reacting with chlorine.
Ca(OH)₂(aq) + Cl₂(g) → CaOCl₂(aq) + H₂O(l)
393
Which elements are found in an uncombined state in nature?
Gold
394
What happens when bromine water is added to potassium iodide solution?
Bromine displaces iodine
395
Which element is found in Period 3 and can displace iodine from sodium iodide?
Chlorine
396
Which greenish gas is denser than air and used in swimming pools to kill germs?
Chlorine
397
What is the nature of metals in terms of electron transfer?
Metals are electropositive; they lose electrons to form positive ions.
398
Which elements are classified as alkali metals?
Group I elements (except hydrogen) are called alkali metals.
399
How reactive are alkali metals
and where are they found?
400
Which group of elements is known as halogens?
Elements of Group VII (Fluorine
401
What is the reactivity and state of halogens in nature?
Halogens are highly electronegative and very reactive; they are found in a combined state.
402
Name three precious metals.
Silver
403
Name some noble metals.
Ruthenium
404
Which metal is soft
and which metal is hard?
405
What happens when bromine water is added to potassium iodide solution?
Bromine displaces iodine
406
Which element is found in Period 3 and can displace iodine from sodium iodide?
Chlorine
407
Which greenish gas is denser than air and used in swimming pools to kill germs?
Chlorine
408
What is the nature of metals in terms of electron transfer?
Metals are electropositive; they lose electrons to form positive ions.
409
Which elements are classified as alkali metals?
Group I elements (except hydrogen) are called alkali metals.
410
How reactive are alkali metals
and where are they found?
411
Which group of elements is known as halogens?
Elements of Group VII (Fluorine
412
What is the reactivity and state of halogens in nature?
Halogens are highly electronegative and very reactive; they are found in a combined state.
413
Name three precious metals.
Silver
414
Name some noble metals.
Ruthenium
415
Which metal is soft
and which metal is hard?
416
What type of electrochemical cell is a Daniell Cell? (a) Electrolytic Cell (b) Galvanic Cell (c) Fuel Cell
(b) Galvanic Cell
417
True or False: In a Daniell Cell, oxidation occurs at the cathode.
False
418
Fill in the blank: The ______ in a Daniell Cell maintains electrical neutrality by allowing ion movement.
Salt Bridge
419
Which metal is used as the anode in a Daniell Cell?
Zinc (Zn)
420
Which metal is used as the cathode in a Daniell Cell?
Copper (Cu)
421
True or False: Electrons flow from the cathode to the anode in a Daniell Cell.
False
422
What is the function of a salt bridge? (a) Prevents solutions from mixing (b) Completes the circuit (c) Maintains electrical neutrality (d) All of the above
(d) All of the above
423
Fill in the blank: In a Daniell Cell, ______ ions move toward the anode, while ______ ions move toward the cathode.
Negative, Positive
424
What is the overall reaction in a Daniell Cell?
Zn + Cu²⁺ → Zn²⁺ + Cu
425
True or False: A Daniell Cell converts electrical energy into chemical energy.
False
426
Fill in the blank: The Daniell Cell produces a standard cell potential of ______ volts.
1.1
427
Which of the following statements is correct? (a) Oxidation occurs at the cathode (b) Reduction occurs at the anode (c) Electrons flow from anode to cathode (d) Zinc gains electrons in the Daniell Cell
(c) Electrons flow from anode to cathode
428
What is the oxidation half-reaction in a Daniell Cell?
Zn → Zn²⁺ + 2e⁻
429
What is the reduction half-reaction in a Daniell Cell?
Cu²⁺ + 2e⁻ → Cu
430
True or False: The Daniell Cell is a spontaneous reaction.
True
431
Fill in the blank: The Daniell Cell consists of a ______ electrode in a zinc sulfate solution and a ______ electrode in a copper sulfate solution.
Zinc, Copper
432
In a Daniell Cell, which electrode gains mass over time?
Copper (Cu) Cathode
433
In a Daniell Cell, which electrode loses mass over time?
Zinc (Zn) Anode
434
True or False: A salt bridge is necessary for electron flow in a Daniell Cell.
False
435
Which ions migrate through the salt bridge from the cathode to the anode?
Negative ions (e.g., SO₄²⁻ or NO₃⁻)
436
Fill in the blank: The Daniell Cell is an example of a ______ cell, which generates electricity from a chemical reaction.
Galvanic
437
Which of the following metals is more reactive? (a) Zinc (b) Copper
(a) Zinc
438
What happens to Zn²⁺ ions in the solution over time? (a) They increase (b) They decrease (c) They stay the same
(a) They increase
439
True or False: Copper sulfate provides Cu²⁺ ions for reduction in the Daniell Cell.
True
440
True or False: A galvanic cell converts electrical energy into chemical energy.
False
441
True or False: In an electrolytic cell, an external power source is required.
True
442
Fill in the blank: In a galvanic cell, the ______ is negative, while in an electrolytic cell, the ______ is negative.
Anode, Cathode
443
What is the purpose of a salt bridge in a galvanic cell? (a) To provide electrons (b) To maintain electrical neutrality (c) To generate power
(b) To maintain electrical neutrality
444
Which type of cell has a spontaneous redox reaction? (a) Galvanic Cell (b) Electrolytic Cell
(a) Galvanic Cell
445
What happens at the anode of a galvanic cell?
Oxidation
446
What happens at the cathode of a galvanic cell?
Reduction
447
True or False: In an electrolytic cell, the cathode is positive.
False
448
Fill in the blank: The movement of electrons in a galvanic cell is from ______ to ______ in the external circuit.
Anode, Cathode
449
What is the role of an external battery in an electrolytic cell?
To drive a non-spontaneous reaction
450
Which electrode supplies electrons in a galvanic cell?
Anode
451
Which electrode gains electrons in a galvanic cell?
Cathode
452
True or False: A dry cell is an example of a voltaic cell.
True
453
Who developed the dry cell in 1887?
Leclanché
454
What metal is used as the anode in a dry cell?
Zinc (Zn)
455
What material acts as the cathode in a dry cell?
Graphite (Carbon Rod)
456
Fill in the blank: The dry cell contains a paste of ______, ______, and ______ as the electrolyte mixture.
Ammonium chloride (NH₄Cl), Manganese dioxide (MnO₂), Carbon (C)
457
What is the oxidation reaction in a dry cell?
Zn → Zn²⁺ + 2e⁻
458
What is the reduction reaction in a dry cell?
2MnO₂ + 2NH₄⁺ + 2e⁻ → Mn₂O₃ + 2NH₃ + H₂O
459
What is the overall reaction in a dry cell?
Zn + 2MnO₂ + 2NH₄Cl → ZnCl₂ + Mn₂O₃ + 2NH₃
460
True or False: A dry cell produces a voltage of approximately 1.25V.
True
461
Fill in the blank: In a dry cell, NH₄Cl acts as an ______.
Electrolyte
462
What is the main disadvantage of a dry cell?
It cannot be recharged
463
True or False: The anode in an electrolytic cell is negative.
True
464
Which type of cell is used in car batteries? (a) Galvanic Cell (b) Electrolytic Cell
(b) Electrolytic Cell
465
What type of battery is commonly used in household devices like remote controls and flashlights?
Dry Cell
466
What is the primary function of a battery?
To convert chemical energy into electrical energy
467
Which electrode is consumed in a dry cell?
Zinc Anode
468
True or False: Electrochemical industries rely on electrochemical reactions to produce various products.
True
469
Fill in the blank: ______ is the process of depositing one metal onto another using electrolysis.
Electroplating
470
What is one example of a chemical manufactured using electrochemical processes?
Sodium hydroxide (NaOH)
471
Which of the following is NOT powered by electrochemical cells? (a) Flashlights (b) Cars (c) Wind turbines
(c) Wind turbines
472
True or False: Electrolytic refining is used to purify metals like copper (Cu).
True
473
Who discovered sodium metal?
Sir Humphry Davy
474
What year was sodium metal discovered?
1807
475
Fill in the blank: Sodium metal is commercially obtained from the electrolysis of molten ______.
Sodium chloride (NaCl)
476
What is the name of the industrial cell used to produce sodium metal?
Downs Cell
477
What is the anode made of in the Downs Cell?
Graphite
478
What is the cathode made of in the Downs Cell?
Iron or copper
479
What is the role of calcium chloride (CaCl₂) in the Downs Cell?
It lowers the melting point of NaCl
480
True or False: The melting point of pure NaCl is 801°C, but adding CaCl₂ reduces it.
True
481
Fill in the blank: In the Downs Cell, sodium ions move to the ______, where they gain electrons and form sodium metal.
Cathode
482
Which of the following is a product of the Downs Cell? (a) Sodium metal (b) Hydrogen gas (c) Oxygen gas
(a) Sodium metal
483
What happens at the cathode in the Downs Cell?
Sodium ions gain electrons and form sodium metal
484
What happens at the anode in the Downs Cell?
Chloride ions lose electrons and form chlorine gas
485
True or False: Chlorine gas is a byproduct of sodium production in the Downs Cell.
True
486
Which equation represents the cathode reaction in the Downs Cell?
2Na⁺ + 2e⁻ → 2Na
487
Which equation represents the anode reaction in the Downs Cell?
2Cl⁻ → Cl₂ + 2e⁻
488
What is the overall reaction in the Downs Cell?
2NaCl → 2Na + Cl₂
489
Fill in the blank: In the Downs Cell, chlorine gas is collected at the ______.
Anode
490
Which of the following is NOT a purpose of electrochemical industries? (a) Electroplating metals (b) Manufacturing plastic (c) Producing sodium metal
(b) Manufacturing plastic
491
True or False: Sodium metal is highly reactive and must be stored in oil.
True
492
What is the primary application of sodium metal in industry?
Manufacturing of chemicals like NaOH and sodium-based alloys
493
True or False: Chloride ions move towards the anode and lose electrons.
True
494
Fill in the blank: The chlorine atoms formed at the anode combine to form ______ gas.
Chlorine (Cl₂)
495
Which equation represents the anode reaction in the Downs Cell?
2Cl⁻ → Cl₂ + 2e⁻
496
Which of the following is NOT a product of the Downs Cell? (a) Sodium metal (b) Hydrogen gas (c) Chlorine gas
(b) Hydrogen gas
497
Fill in the blank: The overall reaction in the Downs Cell is ______.
2NaCl → 2Na + Cl₂
498
True or False: Aluminum is the most abundant metal in the Earth's crust.
True
499
Fill in the blank: The chemical formula of aluminum oxide is ______.
Al₂O₃
500
Why is aluminum never found in its free state in nature?
Because it is highly reactive and forms aluminum oxide.
501
True or False: The protective aluminum oxide layer prevents corrosion.
True
502
In what pH range is the aluminum oxide layer stable?
7.0 to 9.0
503
Which of the following is an amphoteric metal? (a) Iron (b) Aluminum (c) Copper
(b) Aluminum
504
Fill in the blank: Aluminum reacts with both acids and ______.
Bases
505
What is the chemical formula of rust?
Fe₂O₃
506
True or False: Rusting occurs when iron reacts with oxygen and water.
True
507
Which of the following speeds up rusting? (a) Dry air (b) Saltwater (c) Pure oxygen
(b) Saltwater
508
Fill in the blank: ______ is the most stable iron oxide and is known as Magnetite.
Fe₃O₄
509
Which of the following is NOT an iron oxide? (a) FeO (b) Fe₂O₃ (c) Al₂O₃
(c) Al₂O₃
510
Why does saltwater cause faster rusting?
Because sodium ions make iron more reactive.
511
What happens to iron when it rusts?
It expands and forms flaky red layers.
512
True or False: Rusting can weaken iron structures over time.
True
513
True or False: In Nelson's Cell, the anode is made of graphite.
True
514
Fill in the blank: The cathode in Nelson’s Cell is made of ______ and is coated with asbestos.
Steel
515
What are the three products of Nelson’s Cell?
Sodium hydroxide (NaOH), Hydrogen gas (H₂), Chlorine gas (Cl₂)
516
Which equation represents the cathode reaction in Nelson’s Cell?
2H⁺(aq) + 2e⁻ → H₂(g)
517
Which equation represents the anode reaction in Nelson’s Cell?
2Cl⁻(aq) → Cl₂(g) + 2e⁻
518
Fill in the blank: The overall reaction in Nelson’s Cell is ______.
2NaCl + 2H₂O → 2NaOH + H₂ + Cl₂
519
True or False: Sodium ions are reduced at the cathode.
False
520
Why do hydrogen ions get reduced instead of sodium ions in Nelson’s Cell?
Hydrogen ions have a greater tendency to gain electrons than sodium ions.
521
What happens to the Na⁺ ions in Nelson's Cell?
They combine with OH⁻ to form NaOH.
522
True or False: The reaction in Nelson’s Cell makes the solution acidic.
False
523
Which of the following is NOT a product of Nelson’s Cell? (a) NaOH (b) H₂ (c) O₂
(c) O₂
524
Fill in the blank: The purpose of asbestos in Nelson’s Cell is to ______.
Separate the anode from the cathode
525
What environmental issue was caused by asbestos in Nelson’s Cell?
Asbestos is toxic and causes lung problems and cancer.
526
True or False: Asbestos is still widely used in Nelson’s Cell today.
False
527
What has replaced asbestos in modern Nelson’s Cells?
Polymers
528
Why are polymers better than asbestos for Nelson’s Cell?
They are non-toxic and last longer.
529
Fill in the blank: Sodium hydroxide is also known as ______.
Caustic soda
530
Which industry uses NaOH produced from Nelson’s Cell?
Soap and detergent industry
531
True or False: Chlorine gas from Nelson’s Cell is useful in making disinfectants.
True
532
Which gas is collected at the cathode in Nelson’s Cell?
Hydrogen (H₂)
533
True or False: Corrosion is a naturally occurring phenomenon.
True
534
Fill in the blank: The term 'rust' specifically refers to the corrosion of ______.
Iron
535
True or False: Corrosion can happen without moisture or air.
False
536
Which of the following is a common example of corrosion? (a) Rusting of iron (b) Water boiling (c) Ice melting
(a) Rusting of iron
537
Fill in the blank: Corrosion is an _______ process that involves oxidation and reduction.
Oxidation-reduction
538
What is the product of the corrosion of iron?
Ferric oxide (Fe₂O₃ · xH₂O)
539
At the anode during the rusting of iron, iron undergoes ______. (Oxidation/Reduction)
Oxidation
540
True or False: The cathodic reaction during rusting involves the formation of hydroxide ions.
True
541
Which of the following conditions is NOT required for rusting to occur? (a) Air (b) Moisture (c) Complete dryness
(c) Complete dryness
542
Fill in the blank: The electrons lost at the anode move to the cathode, where they react with ______ and ______ to form hydroxide ions.
Water, Oxygen
543
What is the chemical formula for the rust formed from iron corrosion?
Fe₂O₃ · xH₂O
544
True or False: The rusting of iron can only occur in a moist environment.
True
545
Which of the following is an example of the cathodic site during the rusting of iron? (a) Dent (b) Metal exposed to air and water
(b) Metal exposed to air and water
546
True or False: Corrosion is an irreversible process.
True
547
Fill in the blank: Rusting of iron is an example of an _______ reaction.
Electrochemical
548
True or False: In the corrosion of iron, iron acts as the cathode.
False
549
Which of the following is NOT a prevention method for rusting? (a) Painting iron (b) Applying a protective coating (c) Exposing iron to water vapor
(c) Exposing iron to water vapor
550
True or False: Preventing corrosion can be achieved by removing air or moisture from the environment.
True
551
True or False: Corrosion prevention techniques are classified into six groups.
True
552
Which of the following is used to prevent rusting of iron by providing a protective surface? (a) Alloying (b) Paints and coatings (c) Both
(c) Both
553
Fill in the blank: Rusting can be prevented by applying metallic coatings such as _______ plating.
Nickel
554
What is the main purpose of using cathodic protection?
To prevent corrosion by using a better reducing agent to supply electrons
555
Which metal is commonly used in cathodic protection to prevent iron from rusting in pipelines?
Magnesium
556
True or False: Stainless steel resists corrosion due to the alloy of iron, chromium, and nickel.
True
557
What is the role of alloying in preventing corrosion?
It helps protect the metal from corrosion by mixing with other elements like chromium and nickel
558
True or False: Corrosion inhibitors interrupt the chemical reactions that cause rusting.
True
559
Fill in the blank: The method of using a more reactive metal, like zinc, to protect a less reactive metal, like iron, is called _______ protection.
Cathodic
560
Which of the following metals can be used in cathodic protection? (a) Zinc (b) Iron (c) Gold
(a) Zinc
561
Fill in the blank: Metallic coatings, such as those used in electroplating, can protect iron from corrosion by coating it with a metal like _______ or _______ .
Nickel, Chromium
562
True or False: The protective coating of paint also helps to prevent weathering in addition to corrosion.
True
563
What is one method used to remove stains from iron surfaces to prevent rusting?
Cleaning and removing stains
564
True or False: Corrosion inhibitors are only applied as solid coatings, not solutions.
False
565
Which of the following is an example of a chemical used as a corrosion inhibitor? (a) Glycine (b) Sodium chloride (c) Acetic acid
(a) Glycine
566
True or False: Corrosion prevention techniques are classified into six groups.
True
567
Which of the following is used to prevent rusting of iron by providing a protective surface? (a) Alloying (b) Paints and coatings (c) Both
(c) Both
568
Fill in the blank: Rusting can be prevented by applying metallic coatings such as _______ plating.
Nickel
569
What is the main purpose of using cathodic protection?
To prevent corrosion by using a better reducing agent to supply electrons
570
Which metal is commonly used in cathodic protection to prevent iron from rusting in pipelines?
Magnesium
571
True or False: Stainless steel resists corrosion due to the alloy of iron, chromium, and nickel.
True
572
What is the role of alloying in preventing corrosion?
It helps protect the metal from corrosion by mixing with other elements like chromium and nickel
573
True or False: Corrosion inhibitors interrupt the chemical reactions that cause rusting.
True
574
Fill in the blank: The method of using a more reactive metal, like zinc, to protect a less reactive metal, like iron, is called _______ protection.
Cathodic
575
Which of the following metals can be used in cathodic protection? (a) Zinc (b) Iron (c) Gold
(a) Zinc
576
Fill in the blank: Metallic coatings, such as those used in electroplating, can protect iron from corrosion by coating it with a metal like _______ or _______ .
Nickel, Chromium
577
True or False: The protective coating of paint also helps to prevent weathering in addition to corrosion.
True
578
What is one method used to remove stains from iron surfaces to prevent rusting?
Cleaning and removing stains
579
True or False: Corrosion inhibitors are only applied as solid coatings, not solutions.
False
580
Which of the following is an example of a chemical used as a corrosion inhibitor? (a) Glycine (b) Sodium chloride (c) Acetic acid
(a) Glycine
581
Which of the following metals can be used for electroplating to protect another metal? (a) Tin (b) Iron (c) Copper
(a) Tin
582
What is the purpose of electroplating a metal on another metal surface?
To protect the inner metal from corrosion, repair, or decoration
583
True or False: The metal to be electroplated is placed as the anode in the electrolytic cell.
True
584
In the electroplating of tin, what happens at the cathode?
Tin ions are reduced and deposited on the object being plated
585
Fill in the blank: During electroplating, the metal ions from the anode move towards the _______ where they get deposited.
Cathode
586
What is the most commonly used electrolytic solution for electroplating tin?
Sodium stannate
587
True or False: In electroplating, the metal to be plated is cleaned with sand, caustic soda, and water before starting the process.
True
588
What is the main function of the anode in electroplating?
To dissolve and provide metal ions for deposition onto the cathode
589
Which of the following metals is used as an anode in the electroplating of tin? (a) Tin (b) Iron (c) Zinc
(a) Tin
590
True or False: Electroplating can also be used for decorative purposes, such as plating gold or silver onto an inferior metal.
True
591
What is the purpose of the electrolyte in electroplating?
To provide metal ions for deposition on the cathode
592
In electroplating, what happens to the metal at the anode?
It dissolves and forms metal ions in the solution
593
Fill in the blank: In electroplating, the metal ions are reduced at the _______ and deposited on the surface of the object.
Cathode
594
True or False: Electroplating can only be used for protection and cannot be used for decorative purposes.
False
595
Which of the following is used to clean the object before electroplating? (a) Water (b) Caustic soda (c) Sandpaper
(b) Caustic soda
596
True or False: In electroplating of zinc, the object to be plated acts as the cathode.
True
597
What is the electrolyte used in the electroplating of zinc?
Zinc sulfate (ZnSO₄) containing sulfuric acid (H₂SO₄)
598
At the anode in the electroplating of zinc, what happens?
Zinc metal dissolves and converts into Zn²⁺ ions.
599
At the cathode during zinc electroplating, what happens?
Zn²⁺ ions are reduced and deposited as zinc metal.
600
True or False: In electroplating of chromium, the object to be plated acts as the anode.
False
601
What is the electrolyte used in the electroplating of chromium?
Chromic acid (H₂CrO₄) solution containing sulfuric acid (H₂SO₄)
602
In the electroplating of chromium, what happens at the anode?
Chromium ions are produced as chromium dissolves.
603
What happens at the cathode during chromium electroplating?
Chromium ions (Cr₃⁺) are reduced and deposited as chromium metal.
604
True or False: Food and beverages industries use tin-plated steel cans to prevent corrosion and preserve taste.
True
605
Why are tin-plated steel cans used in food and beverage industries?
To prevent corrosion and preserve the taste by avoiding reactions with the can.
606
What does electrochemistry deal with?
The interconversion of electrical energy and chemical energy.
607
Define oxidation in terms of electron transfer.
Oxidation is the addition of oxygen to a substance and/or the removal of electrons.
608
Define reduction in terms of electron transfer.
Reduction is the removal of oxygen from a substance and/or the addition of electrons.
609
What is the oxidation state of an atom?
The apparent charge on an atom due to the loss or gain of electrons.
610
True or False: An oxidizing agent is the species that oxidizes a substance and itself gets reduced.
True
611
True or False: A reducing agent is the species that reduces a substance and itself gets oxidized.
True
612
What is a redox reaction?
A chemical reaction in which oxidation and reduction occur simultaneously.
613
What is an electrochemical cell?
A device where the interconversion of electrical and chemical energy takes place.
614
True or False: An electrolyte is a substance that conducts electricity when dissolved in water or molten.
True
615
What are non-electrolytes?
Substances that do not ionize in solution or in molten state, and therefore do not conduct electricity.
616
What is electrolysis?
The process of chemical decomposition of an electrolyte by passing an electric current.
617
What are electrodes in electrochemistry?
Electrodes are conductors, such as plates, wires, or rods, through which electrons enter or leave the electrolytes in a cell.
618
What is the positive electrode called in an electrochemical cell?
Anode.
619
What is the negative electrode called in an electrochemical cell?
Cathode.
620
What is a voltaic cell?
A cell where oxidation and reduction reactions occur spontaneously and produce electrical energy.
621
What is the Nelson cell used for?
The Nelson cell is used for the preparation of sodium hydroxide (caustic soda) by electrolysis of concentrated aqueous sodium chloride (brine).
622
What is the Down cell used for?
The Down cell is used for the extraction of sodium metal by electrolysis of molten sodium chloride (NaCl).
623
What is electroplating?
Electroplating is the process of depositing one metal over another by means of electrolysis.
624
What is corrosion?
Corrosion is the slow and continuous eating away of a metal by its environment or surrounding.
