Core + Paper 1 Flashcards
1
Q
what is an element?
A
a substance made from atoms that have the same number of protons in the nucleus
2
Q
what is an atom?
A
the smallest particle of an element that still has its chemical properties
3
Q
what is a molecule?
A
a molecule consists of 2 or more of the same atoms that are chemically bonded together
4
Q
what is a compound?
A
a compound consists of two or more different elements chemically joined together
5
Q
what is an ion?
A
an ion is an electrically charged particle
6
Q
How is an Ion formed?
A
an ion is formed when an atom or group of atoms loses or gains electrons
7
Q
who were the 5 scientist that helped discover the structure of the atom
A
Dalton
Thomson
Rutherford
Borh
Chadwick
8
Q
what did Dalton think the atom was
A
dalton thought that the atom was the smallest think and could not be broken into anything smaller
9
Q
what was Thompsons discover
A
Thompson created the plum pudding model where the atom was a sphere of positive with negative electrons dotted around
10
Q
what did Rutherford discover and what was his model
A
Rutherfurd discovered the nucleus(gold foil experiment) and it was a solar system model where there was a positively charged nucleus surrounded by negative electrons in orbit
11
Q
what did Bohr discover about the atom?
A
that the electrons were laid out in shells/ energy levels
12
Q
what did Chadwick discover
A
neutrons
13
Q
what does the (aq) state symbol mean
A
in solution
14
Q
are metal atoms more likely to lose or gain electrons?
A
lose electrons
15
Q
what is the relative mass of an electron?
A
1/1836
16
Q
what is an isotope?
A
An atom with the same number of protons but different amounts of protons
17
Q
who developed the modern periodic table?
A
Mendeleev
18
Q
how did Mendeleev order the periodic table?
A
order of atomic mass
19
Q
What pair of elements did Mendeleev swap
A
tellurium and iodine
20
Q
what were the horizontal rows on the periodic table called?
A
periods
21
Q
what are periods
A
the number of shells that an atom has
22
Q
what were the vertical columns called?
A
groups
23
Q
what did the groups show
A
The number of electrons on the last shell
24
Q
what side are the metals on the periodic table
A
the left side
25
what do you call a positively charged ion?
cation
26
what do you call a negatively charged ion
anion
27
how does the name of a non-metal element change when it becomes a negative ion
add -ide to end
28
How does the name of a negatively charged ion change when it becomes a negative ion that also contains oxygen
add -ate to the end
29
what are ionic bonds?
strong electromagnetic forces of attraction between oppositely charged ions
30
what do you call the structure formed in an ionic compund
lattice
31
do ionic compounds have high or low melting/boiling points?
high melting point
32
why do ionic compounds have high melting and boiling points?
because there are many strong ionic bonds and a large amount of energy must be transferred to the lattice structure to break these bonds
33
do ionic compounds dissolve in water?
yes
34
state why sodium chloride does not conduct electricity in a solid state
the charged particles are not free to move around and carry a current
35
what is a covalent bond?
a bond formed when a pair of electrons are shared between 2 atoms
36
give 3 properties of covalent bonds
- are strong
- formed between non-metal atoms
- often produce molecules which can be compounds or elements
37
how do we model covalent bonds
dot and cross diagrams
38
what are simple molecular substances in terms of their bonding
consist of just a few atoms joined together by strong molecular bonds
39
why do simple molecular substances have low boiling/melting points?
even though there are strong covalent bonds, the molecules are joined together by weak intermolecular forces that are broken during state changes
40
what state are simple molecular substances in at room temp
liquid or gas
41
do simple molecular substances conduct electricity?
no, because their molecules are not electrically charged and there are no electrons that are free to move
42
name a simple molecular substance that dissolves in water
chlorine, carbon dioxide, sulfur dioxide
43
what are giant covalent bonds in terms of their bonding
they consist of many atoms, that are joined by strong covalent bonds and are arranged in a regular lattice structure
44
why do giant covalent bonds have a high boiling temperature?
it is because of how a lot of energy must be transferred to break the many strong covalent bonds during melting and boiling.
45
give 2 examples of giant molecular substances
Diamond and Graphite
46
why does graphite conduct electricity but diamond doesn't
this is because carbon has the ability to form 4 covalent bonds. but in graphite, carbon only forms 3 which means that there is a delocalised electron that is free to move around and carry the current
47
what are some other forms of carbon?
graphene's and fullerenes
48
what is the structure of graphene?
graphene is a giant molecular substance that resembles a single layer of carbon. each atom is connected to three other atoms.
48
what are the 3 properties of graphene?
- graphene conducts electricity because of delocalised electron
- graphene is very strong and flexible due to its strong covalent bonds
- graphene is almost transparent because it is only one atom thick
49
what are the 2 types of fullerenes?
buckyballs and nanotubes
50
give 3 properties of buckyballs
-have delocalised electrons so they can conduct electrons
-the carbon atoms are arranged in pentagons and hexagons
-they are soft when in the solid state because they have weak intermolecular forces
51
give 3 properties of nanotubes
-have closed ends or open ends
-can conduct electricity because they have delocalised electron
-are very strong because the structure has many strong covalent bonds
52
how does the appearance vary on metals to non-metals
metals are shiny
while non-metals are dull
53
how do electrical and conduction vary on metals and non-metals
metals can conduct electricity and are good conductors of heat
while some non-metals are also good conductors but cannot conduct electrical
54
how do density and meting points compare on non-metals and metals?
metals have high melting points and density while
non-metals have low melting points and have a low density
55
what is the opposite of malleable
brittle
56
describe the structure and bondings of metal
- made up of a large lattice of positively charged metal ions and surrounded by a sea of delocalised electrons
- metallic bonds are strong electrostatic forces of attraction between positive metal ions and delocalised electrons
57
why are metals malleable?
layers of ions have the ability to slide over each other and change the shape of the metal without shattering
58
what does ductile mean
the ability to be stretched into a thin wire without shattering
59
what are the five models that can be used to represent atom structure?
- written formulae
- drawn structures
- ball-and-stick diagrams
- space-filling models
- Dot and cross diagrams
60
what are the empirical formulae?
the simplest whole number ratio of atoms of each element
61
what is the symbol for relative atomic mass?
Mr
62
write down the 6 steps to calculating the empirical formula using grams
1. write down the symbol of each element as a header
2. write down the mass of each element (given)
3. write down the atomic mass of each element
4. for each element calculate mass / atomic mass
5. divide each answer by the smallest answer.
6. then multiply the numbers to remove fractions and write down the empirical formulae
63
what is the conservation of mass?
the total mass of reactants and products stays constant during a chemical reaction. The total mass before and after a reaction is the same.
64
what is a closed system?
a closed system is a situation where no substance can enter or leave during a reaction
65
what is the stoichiometry of a reaction?
it has to do with the ratio of the amounts of reactants and products involved when you balance a chemical equation you are finding the stoichiometric equation
66
what is a solution?
a solution is a mixture of a solute in a solvent
67
what is the solvent?
the solvent is the substance that the solute dissolves in
68
what is the solute?
the solute is the substance that dissolves
69
what does dm3 stand for
cubic decimetres
70
what do you need to calculate the concentration of a solution?
the mass of the solute in grams and the volume of the solution in cubic decimetre
71
how many cm cubes is a dm
1000cm3
72
what is the unit of measurement for concentration?
dm-3
73
what is a mole
a mole is the unit for the amount of a substance
74
what is Avagadro's constant?
6.02 * 10^23
75
what is the mass of 1 mole of carbon?
12g
76
what is the formula for moles?
amount(mol) = mass(g)/Mr
77
what is the arrangement of particles like in solids?
close together, regular pattern
78
what is the arrangement of particles like in liquids?
close together, random
79
what is the arrangement of particles like in gases?
far apart, random
80
what is the movement of particles like in solids?
vibrate around a fixed position
81
what is the movement of particles like in liquids?
move around each other
82
what is the movement of particles like in gases?
fast in all direction
83
order the different states of matter. from which has the least stored energy to the most
solids - least
liquid
gasses - most
84
what do call gas to liquid?
condensing
85
what do call liquid to solid?
freezing
86
what do you call solid to liquid?
melting
87
what do call liquid to gas?
boiling./evaporating
88
what do you call gas to solid?
deposition
89
what do you can solid to gas?
sublimation
90
what is an element?
it is a substance that consists only of atoms with the same atomic number
91
what is a compound?
a compound is a substance that consists of two or more different atoms(different elements) that are chemically joined together
92
what 2 structures can elements exist as
atoms or molecules
93
what is a pure substance?
a substance that only contains one element or compound
94
what is a mixture?
a substance that contains different elements and/or compounds that are not chemically joined together
95
what is the difference between impure and pure substances based on their melting point?
pure substances will have a sharp melting point while impure substances will not because it has many different impurities that will each have different melting points
96
what is fractional distillation used for
to separate liquids from a mixture of miscible liquids
97
what is simple distillation used for?
to separate a solvent from a solution
98
explain simple distillation
simple distillation works because the solute will have a higher boiling point than the solvent. so when the solution is heated the solvent will boil, pass into the condenser, cool and collect in the other container while the solute is left.
99
explain fractional distillation
fractional distillation works because the liquids that need to be separated will all have different boiling points. so by heating the mixture up:
- the mixture boils
- hot vapour rises up the column
- vapour condenses when it hits the cool surfaces of the column it condenses and drips back down
- the fraction with the lowest boiling point will reach the top of the column first
- its vapour will then pass into the condenser where it is cooled and transferred into a different container
- if you carry on heating, the vapours from the fractions with higher boiling points pass into the condenser
100
what do you use filtration for
you use filtration to separate an insoluble substance from a liquid or a solution.
101
what do you call the material left in the filter after filtration
residue
102
what do you call the solution created from filtration
filtrate
103
what do you produce with crystallisation?
solid crystals
104
what are the 3 steps to crystallisation?
1. the solution is heated to remove enough solvent to make the solution saturated
3. as the solution cools crystals will form
4. The crystals are then separated from the liquid and dried
105
why do we use a water bath in crystallisation?
to give you more precise control over the temperature
106
why does filtration work?
because the filter paper has tiny pores that are large enough to let dissolved substances through while also being small enough to stop insoluble solid particles going through
107
why does crystallisation work
This is because the solubility of a solvent is higher the higher the temperature. so when a saturated solution cools down the excess solute forms crystals.
108
what is paper chromatography used for
to separate the mixture of soluble substances
109
explain the process of setting up chromatography
1. put spots of the samples you want to separate onto the paper and label them with a pencil.
2. put the paper into liquid, but make sure it does not reach the level of the inks.
3. as the water moves up the sheet of paper the water will dissolve the samples.
110
explain how chromatography works
chromatography works as the more soluble compounds are carried up the paper faster than less soluble ones, which makes the compounds separate.
111
what are the 2 phases of chromatography?
- stationary phase
- mobile phase
112
what is the stationary phase in chromatography?
a substance that does not move
113
what is the mobile phase in chromatography?
a substance that moves through the stationary phase - the solvent
114
what can the Rf be used for
identify different substances
115
how do you know if a substance is pure or not using chromatography?
a pure substance will only have 1 spot while a compound will have more than one spot
116
what are the formulae for finding the RF value?
distance travelled by spot/distance travelled by solvent
117
what are two features that potable drinking water must have
low levels of contaminating substances
low levels of microbes
118
what are the 3 phases of water treatment?
sedimentation
filtration
chlorination
119
what happens in the sedimentation stage of water treatment
the water is left to rest so that the large insoluble particles sink to the bottom of the tank
120
what happens in the filtration stage of water treatment
small insoluble particles are removed by filtering through sand and gravel
121
what happens in the chlorination stage of water treatment
chlorine gas is bubbled through water to kill microbes
122
what process can be used in seawater treatment?
simple distillation
123
what are the 2 positives of treating seawater?
- there is plenty of seawater
- produces pure water by killing microbes
124
what is a negative of using distillation for the treatment of seawater?
needs a lot of energy to heat the water
125
what are the 3 properties of acids?
- have a PH less than 7
- they are a source of hydrogen ions (Hydrochoric acid produces h+ ions)
- the higher the concentration of H+ the lower the PH of the acidic solution
126
what are the 3 properties of alkalis?
- the PH is greater than 7
- they are a source of hydroxide ions (sodium hydroxide releases OH- ions)
- the higher the concentration of OH- ions the higher the pH of the solution
127
what is the range of the PH scale?
0-14
128
what colour does the universal indicator go if the solution is acidic
red
129
what colour does the universal indicator go if the solution is alkaline
blue/purple
130
what colour does litmus paper go if the solution is acidic?
red
131
what colour does litmus paper go if the solution is alkaline?
blue
132
what colour does phenolphthalein go if the solution is acidic?
colourless
133
what colour does phenolphthalein go if the solution is alkaline?
pink
134
what colour does methyl orange go if the solution is acidic?
red
135
what colour does methyl orange go if the solution is alkaline?
yellow
136
how can you change a concentrated solution to a dilute solution?
by adding more water
137
how can change a dilute solution into a concentrated solution?
add more solute
evaporate some of the water
138
1cm cubed of 2 mol dm-3 is added to 4sm cubed of water what is the new concentration
1/5 * 2 = 0.4 mol dm-3
139
why are hydrochloric acid and sulfuric acid strong acids
because they fully dissociate into ions when added to the solution, and since the concentration of H+ ions is what determines the strength of the solution they are both strong acids.
140
what does dissociation mean
the process in which molecules separate into ions
141
why is ethanoic acid weak?
because it only partially dissociated into ions in solution. and since the concentration of H+ ions is what determines the strength of an acid, it is weak
142
what does it mean when it says that alkali metals have a soluble base?
one that dissolves in water
143
what is a base (acids and alkali topics)
any substance that reacts with acids to form salt and water only
144
what are bases normally (acids and alkali topics)
they are usually metal hydroxides
145
what is the simple word equation for a reaction between a base and an alkali.
base + acid --> salt + water
146
how do salts form (acids and alkali topics)
they form when hydrogen ions in an acid are replaced by metal ions or ammonium ion
147
how do we name salts?
metal in base + acid name
sodium hydroxide + hydrochloric acid ---> sodium chloride
148
what does a metal + acid make
metal + acid ---> salt + hydrogen
149
what does a metal carbonate and an acid make
metal carbonate + acid --> salt + water + carbon dioxide
150
what test do we use to test for hydrogen?
hydrogen splint pop test, the lighted splint will ignite the hydrogen and make a pop sound
151
how do we test for carbon dioxide?
carbon dioxide will turn lime water milky or cloudy white
152
what are the 3 steps for the practical use of making salts from insoluble bases?
1. add an excess base to the acid
2. filter the excess base from the solution
3. slowly evaporate solution to get crystals
153
what are the 3 steps for the practical use of making salts from soluble bases?
1. use titration to find the exact volume of the soluble base that is needed to react it with the acids
2. mix the acid and the soluble in the correct proportions to produce a perfectly saturated solution
3. warm the solution to evaporate the water and leave salt crystals behind
154
what are the 6 steps of titration?
1. put acid into the burette
2. use a pipette to put a known volume of alkali into the conical flask
3. put a few drops of indicator into the conical flask
4. record the amount of acid in the burette
5. add acid to the alkali until the colour changes
6. record the end amount of acid left and calculate how much acid was needed to neutralise the acid
155
what is the Titre
the tire is the exact volume needed to exactly neutralise an acid
156
what are the 6 different chemical types that will form a soluble solution?
- common sodium salts
- common potassium salts
- common ammonium salts
- all nitrates
- common chlorides
- common sulfates
157
what 3 hydroxides that are soluble
sodium hydroxide
potassium hydroxide
ammonium hydroxide
158
what 3 carbonates that are soluble
sodium carbonate
potassium carbonate
ammonium carbonate
159
what are 2 chloride exceptions that are insoluble?
silver chloride
lead chloride
160
what are 3 sulfate exceptions that are insoluble?
lead sulfate
barium sulfate
calcium sulfate
161
what are 2 chemical types that produce insoluble salts?
common hydroxides
common carbonates
162
what is electrolysis used for
it is used to decompose ionic compounds in the molten state or dissolved in water
163
what is an electrolyte?
an ionic compound in a molten or dissolved state
164
what is the definition of electrolysis?
a process in which electrical energy from a direct current supply decomposes an electrolyte
165
what is an anion?
negatively charged ions that move to the positively charged electrode (anode)
166
what is a cation?
positively charged ions that move the (cathode)
167
what is the charge of the cathode
negative
168
what is the charge of the anode?
positive
169
what happens to the anion during electrolysis
oxidised
170
what happens to the cation during electrolysis
reduced
171
what ions does water change into
H+ and HO-
172
what happens at the cathode when electrolysis happens in a solution
at the negative electrode, hydrogen will be produced unless the compound contains ions from a metal less reactive than hydrogen, in which case a metal is produced
173
give 2 metals that are below hydrogen in the reactivity series
copper and silver
174
what happens at the anode when electrolysis happens in a solution
oxygen is produced unless the compund contains halides in which case the anode will make a halide molecule with 2 of the halide
175
what are the products when a metal with a reactivity higher than hydrogen reacts with water
metal + water --> metal hydroxide + hydrogen
176
what is produced when a metal reacts with an acid
metal + acid --> salt + hydrogen
177
true or false "The rate of reaction is greater in a metal if the acid is cold,"
false
178
give an exception for metals that don't react with water even though they are more reactive than hydrogen and give a reason
- aluminium = It has a layer of aluminium oxide that stops the water from reaching the metal below
179
give an exception for metals that surprisingly slowly react with water even though they are more reactive than hydrogen and give a reason
- magnesium = a layer of sparingly soluble magnesium hydroxide forms which slows the reaction
180
give an exception for metals that don't react with acid even though they are more reactive than hydrogen and give a reason
in the reaction of calcium with dilute sulfuric acid
181
give the reactivity series in order from most to least reactive
(Please Stop Calling Me A Zebra I,ll Her Calling Me A Super Powerful Giraffe)
-potassium
-sodium
-calcium
-magnesium
-aluminium
-zinc
-Iron
-hydrogen
-copper
-mercury
-Silver
-platinum
-gold
182
what happens in a metal displacement reaction
a more reactive metal will displace a less reactive metal from its salt
183
explain how metal displacement reactions are redox
- the atoms of the more reactive metal are oxidised - lose electron
- the metal cations of the less reactive metal are reduced - they gain electrons
184
how does a metal form a cation
metal atoms lose electrons to form cation
185
metals react with water to form :
metal hydroxides
186
metals react with dilute acids to form
salts
187
why are some metals more reactive than other
because the more reactive metal gives away its outer electron easier to form a cation
188
what is an ore?
an ore is a rock that contains a metal that can be extracted
189
how can reduce a metal oxide to just a metal?
heat it with carbon or hydrogen to create metal + carbon dioxide
190
name a way to extract metal from ores
electrolysis
191
why is electrolysis not used to extract all metals?
because it requires constant electricity which is expensive
192
name 5 metals that are extracted from ores by electrolysis
potassium
sodium
calcium
magnesium
aluminium
193
give the 3 methods that are used to extract metals from ores
electrolysis
reduction
displacement reaction
194
what methods of extraction are used to extract elements less reactive than carbon
reduction
195
how can you use reducing to extract ores?
by reducing metal oxide to metal and carbon dioxide
196
what is a biological method of extracting metal from ores?
phytoextraction
bioleaching
197
how does phytoextraction work
by getting plants to absorb the metal compounds through it's roots and then burning the plants the ash will contain metal compounds
198
what are the 3 disadvantages of extracting metals from ores?
uses up limited resources
uses a lot of energy
damages the environment
199
what are the 4 advantages of recycling metals?
metal ores will last longer
less energy is needed
fewer quarries and mines are needed
less noise and dust are produced
less land is needed
200
what are the 3 negatives of recycling metals?
used metal items must be collected and transported to the recycling centre
different metals must be removed from used items and sorted
recycling saves different amounts of energy depending on the metal involved
201
what is a life cycle assessment?
is a cradle-to-grave analysis of the impact of an item on the environment
202
what are the 4 stages of a life cycle assessment?
- obtaining raw materials
- manufacturing the product
- using the product
- disposing of the product
203
what are the 6 factors that a LCA will need?
an LCA is likely to need data on these factors at most or all stages;
- the use of energy
- the release of waste materials
- transport and storage
an LCA is also likely to need data on
- whether the raw materials needed are renewable or non-renewable
- whether any of the products can be reused or recycled
- how the product is disposed of
204
where are transitional metals found?
they are placed between groups 2 and 3
205
what are 2 typical physical properties of transitional properties?
high melting point
high density
206
what are 2 chemical properties of transitional properties?
formation of coloured compounds
can be catalysts
207
what are 4 chemical and physical properties of group 1 and 2 metals?
relatively low melting points
relatively low density
formation of white or colourless compounds
lack of catalytic activity
208
which process is iron a catalyst for
the Haber process
209
what does the oxidisation of metals result in
corrosion
210
what is the name given to the corrosion of iron and steel?
rusting
211
what 2 things does iron need to rust
oxygen and water
212
what are the 4 prevention methods used to stop the rusting of iron? (keeping water + oxygen away from it)
painting
using oil and grease
coating with plastic
coating with another metal
213
give one way to keep oxygen away from iron to prevent rust
store the iron in a vacuum
214
give one way to keep water away from iron to prevent rust
put the item in a container with a desiccant
215
what is desiccant
something that absorbs water vapour
216
what are the benefits of electroplating iron/steel?
improves its appearance
improves its resistence to corrosion
217
what happens in electroplating
a thin layer of unreactive metal such as nickel, silver or gold is deposited on the surface of the metal object to keep air and water out
218
what is the name of the process of coating iron/steel objects with a thin layer of zinc to prevent them from rusting
galvanising
219
how does galvanising work
by coating iron or steel with a more reactive metal the oxygen and water will corrode the zinc instead of the iron/steel
220
what is an alloy?
a mixture of metal with one or more other elements, these elements are usually other metals or carbons
221
what is steel made out of
iron mixed with carbon
222
what is stainless steel made out of
iron and chromium
223
how does stainless steel resist corrosion?
the layer of chromium will form an invisible thin layer of chromium oxide that forms on the surface of the steel and prevents air and oxygen from reaching the iron
224
what is magnalium made out of
aluminium and magnesium
225
what are some properties of magnalium?
low density
226
what is magnalium used for
cars and aeroplanes
227
what is jewellery gold made out of
gold and copper
228
what are some typical properties of jewellery gold?
attractive, resistant to corrosion
229
what is brass made out of
copper and zinc
230
what are some typical properties of brass?
hard
resistant to corrosion
good electrical conductor
231
what is brass used for
electrical plugs and coins
232
why does adding carbon to iron make it stronger
the larger carbon atoms will stop the layers of pure iron from sliding over each other relatively as the large carbon atoms will disrupt the layers and prevent the layers from sliding over each other
233
what is the formula for calculating the concentration?
concentration = amount of solute/volume of solution
234
what is the unit for measuring concentration?
mol/dm-3
235
how do you convert from mol dm-3 to g/dm3
multiply by Mr
236
what is the yield in chemistry?
the mass of the product made in a chemical reaction
237
what are the 3 types of yields in chemistry?
theoretical yield
actual yield
percentage yield
238
what is the theoretical yield?
the maximum amount of product that can be made
239
what is the actual yield?
the mass of the product that you really get at the end of a reaction, this is always less than the theoretical yield
240
what are 3 reasons why the yield in chemical reactions is less than usual
incomplete reactions if the reaction reaches an equilibrium
practical losses during the experiment
side reaction
241
what is the formula for percentage yield?
(actual yield / theoretical yield) * 100
242
what is atom economy?
a way of measuring the atoms wasted when making a substance
243
what 2 things do you need to know to calculate the atom economy?
the relative formula masses of the products
the balanced equation for the reaction
244
what is the formula to calculate atom economy?
total Mr(formula masses) of useful product
----------------------------------------------------*100
total Mr of all products
245
what is Avagadro's law on molar gases?
it states that equal volumes of gas at the same temperature and pressure will have the same number of molecules
246
what are the 3 factors that affect the volume occupied by a gas?
- the number of particles present
- the temperature of the gas
- the pressure of the gas
247
what does the molar volume mean in terms of gas?
the amount of volume occupied by one mole of a gas at room temp and atmospheric pressure or 24 dm3/mol
248
what is the formula for the volume of gas?
molar volume * amount
249
what is the equation for finding the mass of a gas?
Mr * amount
250
what are reversible reactions?
the direction of some reversible meaning that the direction of the reaction can be altered by changing the conditions
251
what is a dynamic equilibrium?
when the forward rate of a reversible reaction is the same as the backward rate of a reaction.
252
what is the Haber process?
is a reversible reaction between nitrogen and hydrogen that forms ammonia. n2+ 3h2 --> 2nH3
253
what are some conditions needed for the Haber process?
iron catalyst
200 atmosphere
450 temperature
254
what 4 factors affect the position of the equilibrium in a chemical reaction
temperature
pressure
the concentration of the reacting substance
catalyst added
255
what happens to the position of the equilibrium and the rate at which it will be reached if temperature is increased
it will move in the direction of the endothermic reaction
and the rate is increased
256
what happens to the position of the equilibrium and the rate at which it will be reached if pressure is increased
the equilibrium will move in the direction of the fewest molecules of gas and the rate will be increased
257
what happens to the position of the equilibrium and the rate at which it will be reached if concentration is increased
will move in the direction away from the reacting substance and the rate is increased
258
what happens to the position of the equilibrium and the rate at which it will be reached if a catalyst is added
no change in the position of equilibrium but the rate is increased
259
what factors affect the conditions chosen for industrial processes
the availability of raw materials and energy supplies.
the control of temperature and pressure
the use of a suitable catalyst
260
what 3 chemicals help plants grow
nitrogen
phosphorus
potassium
261
what soluble compund is added to fertilisers to supply nitrogen
nitrate and ammonium salts
262
what soluble compund is added to fertilisers to supply phosphorus
phosphate salts
263
what soluble compund is added to fertilisers to supply potassium
potassium salts
264
why is ammonium used in fertilisers?
they are a source of soluble nitrate
265
how is ammonium sulfate created in labs?
ammonium solution and dilute sulfuric acid are brought from chemical manufacturers. the process involves only a few stages (titration then crystallisation) but only every little product is made
266
how is ammonium sulfate created in factories?
will use natural gas, air and water (raw materials needed to make ammonia)
sulfur, air and water will be used to make sulfuric acid
this process will involve many stages but a lot of produce will be made
267
what are 2 ways that can be used to create a voltage?
chemical cells and fuel cells
268
what are the steps to make a simple chemical cell?
make one beaker with zinc dipped in zinc sulfate solution and another with copper dipped in copper sulfate solution. connect the 2 metals with crocodile clips wired to a voltmeter. connect the 2 solutions with filter paper soaked in KCl
269
how does a chemical cell work
electrons will flow through the zinc and copper because zinc is more reactive. Ions will pass through the filter paper completing the circuit.
270
what is a hydrogen-oxygen fuel cell?
where hydrogen and oxygen are used to make a voltage. and where water vapour is the only product.
271
what are 2 advantages of chemical cells?
suitable for portable devices
are cheap to manufacture
272
what are 2 disadvantages of chemical cells?
may contain harmful substances
do not produce voltage when one of the reactants run out
273
what are 2 advantages of hydrogen-oxygen fuel cell?
produce water as only waste product
produce a voltage as long as the fuel and air are supplied
274
what are 2 disadvantages of hydrogen-oxygen fuel cell?
are not suitable for portable devices
are expensive to manufacture
