Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

GCSEs > Chemistry (Paper 1) > Flashcards

Chemistry (Paper 1) Flashcards

1
Q

Who developed the periodic table?

A

Dmitri Mendeleev

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Who created the Billiard Ball Model?

A

Dalton

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What model did JJ Thompson propose?

A

The plum pudding model

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Who created the Bohr model?

A

Rutherford

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What type of elements are involved in ionic bonding?

A

A metal and non metal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Relative mass of an electron

A

0

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is an ion?

A

A charged atom

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What type of bonding involves only non metals?

A

Covalent bonding

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Ionic bond definition

A

Electrostatic attraction between oppositely charged ions (when electrons are transferred from metal atoms to non metal atoms)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Electrostatic force

A

A force of attraction between particles with opposite charges

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is filtration?

A

Method that separates an insoluble solid from a liquid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Ionic compounds exist as

A

Giant ionic lattices

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Electricity definition

A

A flow of charge

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Why do ionic lattices have high melting and boiling points?

A

Large amounts of energy is required to break the strong ionic bonds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Why do ionic lattices only conduct electricity when liquid or dissolved in water

A

The ions are free to move and so charge can flow through the structure.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

The number of electrons an atom needs to get a full outer shell in covalent bonding is equal to

A

the number of bonds that an atom can form

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Intermolecular force

A

A force between molecules

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Weak intermolecular forces are overcome when..

A

simple molecular structures melt or boil

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Simple molecular structures have no

A

overall charge

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Covalent bond definition

A

Shared pair of electrons (between non metals)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Simple molecular structures are usually liquids or gases because

A

the intermolecular forces are so weak, not much energy is required

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

small molecules have a low boiling point whilst large molecules have a higher boiling point because..

A

as the size of the simple molecule increases so does the strength of the intermolecular forces therefore more energy is required to break/overcome the forces

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What element is diamond, graphite and fullerene made of?

A

Carbon

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Polymers are

A

Long chain of molecules held together by strong covalent bonds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Why are polymers solid at room temperature?

A

The intermolecular forces are relatively strong.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Polyatomic ions definition

A

• Ions made from more than one charged atom (and are covalently bonded together)
• Eg Nitrate (NO3 -)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Formula for Nitrate

A

NO3-

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Sulfate formula

A

SO4 2-

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Hydroxide formula

A

OH-

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Carbonate formula

A

CO3 2-

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Ammonium formula

A

NH4 +

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Pure metals are (soft/hard)

A

Soft

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Alloys are (soft/hard)

A

Hard

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Why are pure metals soft?

A

The atoms are the same size therefore they are in an orderly arrangement and layers are able to slide over each other (malleable)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

Why are alloys hard?

A

The atoms are different sizes therefore there is a disorderly arrangement and the layers are distorted. Therefore layers can’t slide over each other

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

Molecule definition

A

Atoms chemically bonded together

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

Why is a diamond very hard?

A

• It is a giant covalent lattice with 4 strong covalent bonds between each atom
• A large amount of energy is required to break the bonds apart

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

Allotrope definition

A

A different structural form of an element eg Diamond and Graphite

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

What does PANIC stand for?

A

Positive Anode, Negative Is Cathode

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

Graphene

A

• A single layer of graphite
• Used for drug delivery or in electronics

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

Properties of transition metals (1)

A

• Less reactive than group 1 metals
• shiny and malleable
• sonorous
• electricity and heat conductor

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

Properties of transition metals (2)

A

• catalysts for chemical reactions
• form coloured compounds
• high melting and boiling points
• able to have different charges

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

Electroplating definition

A

Using electrolysis to coat an object in a thin layer of a metal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

What is electroplating used for?

A

To protect objects from corroding or to improve its appearance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

What is the structure of a metal?

A

A lattice of positive metal ions attracted to delocalised electrons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

Alloy definition

A

Mixture of a metal with small amounts of other elements

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

What elements are found in steel?

A

Iron (main element) and carbon

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

What elements are found in brass?

A

Copper (main element) and zinc

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

What elements are found in bronze?

A

Copper (main element) and tin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

What elements are found in an aluminium alloy (aka magnalium)

A

Aluminium (main element) and magnesium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

Corrosion definition

A

Destruction of materials by reaction with water and/or oxygen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

Rusting definition

A

Corrosion of iron or steel

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

Electrolyte definition

A

an ionic compound that is dissolved in water and conducts electricity during electrolysis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

Positive electrode

A

Anode

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

Negative electrode

A

Cathode

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

Why do solid ionic compounds not conduct electricity?

A

Their ions aren’t free to move therefore charge is unable to flow through the structure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
57
Q

What is zinc beneficial for?

A

killing bacteria

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
58
Q

How does sacrificial protection work?

A

When a more reactive metal is used to coat a metal so that it corrodes instead

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
59
Q

Empirical formulae meaning

A

The simplest whole number ratio of atoms or ions in a substance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
60
Q

How are chemical reactions sped up?

A

By heating them

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
61
Q

How to find empirical formula?

A

• Mass or percentage of the atom/ion over the atomic masses
• Divide results by the smallest answer
• Use the ratio as the subscripts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
62
Q

Concentration equation

A

Mass/Volume

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
63
Q

Negative ion

A

Anion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
64
Q

Methods for corrosion prevention

A

Electroplating and sacrificial protection

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
65
Q

unit for concentration

A

g dm-3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
66
Q

Law of conservation of mass

A

The mass of reactants and products are the same in a reaction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
67
Q

Mole meaning

A

Unit for measuring the number of particles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
68
Q

Relationship between a mole and Avogadro’s constant

A

1 mole of a substance contains 6.02 x10^23 particles of that substance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
69
Q

RFM meaning

A

Relative formula mass (sum of atomic masses of the elements in the molecule)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
70
Q

How can the concentration of a solution be increased?

A

•Increasing the mass of the solute • decreasing volume of solvent

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
71
Q

Concentration definition

A

How much solute is dissolved in a volume of solvent

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
72
Q

Equation to work out the Mass of a substance

A

Mr x moles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
73
Q

1 dm3 =

A

1L or 1000cm3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
74
Q

Experiment to find the mass of oxygen reacting with magnesium

A

• strongly heat magnesium ribbon in crucible • lift lid occasionally to let in oxygen • measure mass of magnesium oxide at end • subtract the mass of magnesium at start

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
75
Q

1 ton = how many grams

A

1,000,000 grams

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
76
Q

1 mg = how many grams

A

1/1000 grams

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
77
Q

1 mole of a substance weighs the same as

A

the Ar or Mr of the substance (in grams)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
78
Q

What are the 4 separation techniques?

A

filtration, crystallisation, distillation and chromatography

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
79
Q

Crystallisation

A

• To make crystals out of a solution by evaporating it
• Separates a soluble salt from a solution

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
80
Q

How to calculate percentage yield

A

Actual yield / theoretical yield x 100

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
81
Q

Toxic meaning

A

Something that causes death

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
82
Q

Why are reagents used in excess?

A

To ensure all of the other reactant reacts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
83
Q

What does reagent mean?

A

Reactant

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
84
Q

Limiting reagent meaning

A

A reagent not in excess that limits how much product is made

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
85
Q

Yield definition

A

The mass of product produced by a chemical reaction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
86
Q

Stoichiometry meaning

A

Ratio of moles that react

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
87
Q

Why do some reactions produces a small yield?

A

• Unwanted side reactions
• Incomplete reactions
• Product left behind on apparatus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
88
Q

What are the diatomic elements?

A

hydrogen (H), nitrogen (N), oxygen (O), fluorine (F), chlorine (Cl), bromine (Br), and iodine (I)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
89
Q

What is concentration measured in (using moles)?

A

Mol/dm³

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
90
Q

Equation to work out moles (from the concentration of a solution)

A

Concentration x volume

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
91
Q

Unit for measuring volume

A

dm³

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
92
Q

What’s a titration?

A

An accurate method to measure the concentration of acids and alkalis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
93
Q

How are titrations carried out?

A

Measure the volume of an acid in a burette needed to exactly neutralise an alkali (which has been measured into a conical flask with a pipette)

94
Q

How to calculate atom economy %

A

(Mr of desired product \ Mr of all products) x 100

95
Q

How to calculate volume (Avogadro’s law)

A

24 x moles

96
Q

What is Avogadro’s Law?

A

1 mole of any gas (at room temperature and pressure) has a volume of 24 dm³

97
Q

[Topic 3]
State symbol for aqueous

A

aq

98
Q

What makes a solution acidic?

A

Positive hydrogen ions (H+)

99
Q

Bases meaning

A

Substances which can neutralise an acid, forming a salt and water

100
Q

Alkali meaning

A

A base that can dissolve in water to produce hydroxide ions in a solution

101
Q

What are the most common bases?

A

• Metal oxides eg CaO
• Metal hydroxides eg Ca(OH)2
• Metal carbonates CaCO3

102
Q

What substance do alkalines produce in water?

A

Negative hydroxide ions (OH-)

103
Q

Wasp stings are

A

Basic

104
Q

Bee stings are

A

Acidic

105
Q

What are indicators?

A

Substances that change colour when added to an acid or alkali

106
Q

How does a litmus indicator function?

A

In an acidic solution: It turns red
In an alkaline solution: It turns blue
In a neutral solution: It doesn’t change colour

107
Q

How does the phenolphthalein indicator function?

A

In an acidic solution: It’s colourless
In an alkaline solution: It turns pink

108
Q

How does a methyl orange indicator function?

A

In an acidic solution: It turns red
In an alkaline solution: It turns yellow

109
Q

How can pH be measured?

A

• Universal Indicator solution • Digital pH meter

110
Q

Apparatus used in a titration

A

• Bunsen burner • Burette • Glass pipette • Indicator • Conical flask • Acid and alkali

111
Q

What are common acids?

A

• Sulfuric acid (H₂SO₄)
• Hydrochloric acid (HCL)
• Nitric acid (HNO₃)

112
Q

Symbol equation for dissolved hydrochloric acid

A

HCL (aq) —> H+(aq) + Cl-(aq)

113
Q

Symbol equation for dissolved sodium hydroxide (Alkali)

A

NaOH (aq) —> Na+(aq) + OH-(aq)

114
Q

What does green indicate on a universal indicator?

A

The substance is neutral

115
Q

What happens when an acid reacts with an alkali

A

Neutralisation occurs • The H+ ions react with OH- ions to produce water

116
Q

Word equation and ionic equation for the reaction between an acid and alkali

A

Acid + alkali —> salt + water

H+ + OH- —> H2O

117
Q

What happens to the pH of an acidic solution as it reacts with a base

A

• The pH increases slowly at first because there’s excess H+ ions
• Increases rapidly as more OH- ions from the alkali is added
• Then increases at a slower rate because there’s excess OH- ions

118
Q

Chemical formulae for acids

A

Sulfuric acid - H₂SO₄
Nitric acid - HNO₃
Hydrochloric acid - HCl
Ethanoic acid - CH₃COOH

119
Q

Common salts

A

Sulfates
Chlorides
Nitrates
Phosphates
Ethanoates
Citrates

120
Q

Common alkalis and their formulae

A

Ammonia NH3
Calcium hydroxide Ca(OH)₂

121
Q

Dilute acids have

A

Few H+ ions in the solution

122
Q

Concentrated acids have

A

Lots of H+ ions in the solution

123
Q

What happens when acids dissolve in water?

A

They ionise (separate into ions) to release hydrogen ions in the solution

124
Q

What makes an acid strong?

A

When the molecules ionise fully

125
Q

What makes an acid weak?

A

When the molecules only ionise partially

126
Q

In a weak acid, the reaction is ________

A

Reversible

127
Q

Ionic equation for weak acids

A

HX ⇌ H+ + X-

128
Q

How is pH value calculated?

A

Using the concentration of hydrogen ions in a solution

129
Q

What would decreasing the pH of a solution by 1 do?

A

It would increase the concentration of H+ ions by a factor of 10

130
Q

Metal + acid —>

A

Salt + hydrogen

131
Q

Metal oxide + acid —>

A

Salt + water

132
Q

Metal hydroxide + acid —>

A

Salt + water

133
Q

Metal carbonate + acid —>

A

Salt + water + carbon dioxide

134
Q

Ammonia + acid—>

A

Ammonium salt

135
Q

Test for hydrogen

A

When a lit splint goes out with a squeaky pop

136
Q

Test for carbon dioxide

A

When you bubble the gas through limewater and it turns cloudy white

137
Q

Method to make pure dry crystals of a salt
(Making a soluble salt from an insoluble base)

A

• Add the [named insoluble base] to the [named warm acid] until the base is in excess
• Filter the solution to remove the excess base
• Pour the filtrate into an evaporating basin and gently heat it to evaporate some water
• Stop heating when half the solution remains
• Leave the solution to evaporate
• Filter, wash and dry the crystals

138
Q

When a solution ends in -ate what does it contain?

A

Oxygen

139
Q

How to make a soluble salt using a soluble reactant

A

Acid-alkali titration:

• Do a trial run to show roughly what volume is needed for neutralisation

• Perform several attempts and calculate a mean volume using reproducible results

• After establishing the required volume repeat the neutralisation reaction without indicator

• Obtain the solid salt by evaporation/crystallisation

140
Q

Methods to produce a salt

A

• Making a soluble salt from an insoluble base (evaporation)
• Making a soluble salt using a soluble reactant (titration)
• Making an insoluble salt using soluble salts (filtration)

141
Q

How to prepare an insoluble salt

A

• Two soluble salt solutions are mixed together in a beaker and a white precipitate of the insoluble salt is formed

• The precipitate is filtered off

• The filtered precipitate is washed several times with deionised (pure) water which prevents a reaction with the salt from occurring

• The insoluble salt is carefully scraped off the filter paper into a dish and dried in an oven

142
Q

Substances soluble in water

A

• Sodium, potassium and ammonium compounds (carbonates and hydroxides)
• All nitrates
• Most chlorides
• Most sulfates
• Calcium hydroxide

143
Q

Substances insoluble in water

A

• Silver chloride
• Lead chloride

• Lead sulfate
• Barium sulfate
• Calcium sulfate

• Most carbonates
• Most hydroxides

144
Q

Zinc ion formula

A

Zn (2+)

145
Q

Oxide ion formula

A

O (2-)

146
Q

Nitride ion

A

N (3-)

147
Q

Electrolysis meaning

A

The breakdown of an ionic compound using electricity

148
Q

The electrolyte must be..

A

Molten or in an aqueous solution

149
Q

Positive ion

A

Cation

150
Q

Negative ion

A

Anion

151
Q

Why can electrolytes only conduct electricity when molten or in solution

A

The ions are free to move therefore charge can flow

152
Q

How is indicator paper used to determine the pH of a mixture?

A

• Look at the colour of the indicator
• Compare it to the chart

153
Q

When the air hole of a Bunsen burner is open, the flame is

A

a roaring blue flame

154
Q

Methane (CH4) exists as a

A

simple molecule

155
Q

Graphite has a (high/low) melting point because

A

• High
• It’s a giant covalent lattice where the atoms are strongly bonded together
• A large amount of energy is required to break them apart

156
Q

OILRIG acronym

A

• Oxidation is Loss
• Reduction is Gain

157
Q

What word is used to remember the process that occurs at the anode?

A

Anox
(Anode oxidation)

158
Q

What word is used to remember the process that occurs at the cathode?

A

Redcat
(Reduction cathode)

159
Q

Half equation for chlorine

A

2Cl - -> Cl2 + 2e -

160
Q

Half equation for zinc

A

Zn2+ + 2e - -> Zn

161
Q

Rules for electrolysis of an aqueous electrolyte

A

• The least reactive cation is reduced at the cathode
• If a halide is present the halogen is produced at the anode
• If there isn’t, oxygen is produced at the anode

162
Q

Half equation for oxygen produced in the electrolysis of an aqueous solution

A

4OH - —> 2H2O + O2 + 4e-

163
Q

What process happens at the anode?

A

Oxidation (losing electrons)

164
Q

What process happens at the cathode?

A

Reduction (gaining electrons)

165
Q

Observation at anode during electrolysis of copper sulfate solution

A

The electrolyte bubbles (oxygen is present)

166
Q

Observation at cathode during electrolysis of copper sulfate solution

A

Red-brown solid (copper)

167
Q

Why must the electrodes be inert?

A

So that the electrodes themselves do not react with the ions in the solution

168
Q

Inert meaning

A

Unreactive

169
Q

Using copper electrodes in electrolysis

A

• For a copper anode, the copper atoms lose electrons to the powerful electrical current
• This forms Cu 2+ ions

• The Cu 2+ ions enter the electrolyte and are attracted to the cathode
• The ions are then discharged and deposited as copper atoms

• As the anode breaks down any impurities remain in the electrolyte

170
Q

Why does the mass of the anode change during electrolysis using copper electrodes?

A

• It gets lighter because it loses copper
• The copper atoms are oxidised and lose 2 electrons to become copper ions that dissolve into the electrolyte

171
Q

Why does the mass of the cathode change during electrolysis using copper electrodes?

A

• It gets heavier because it gains copper
• Copper ions are reduced and gain 2 electrons to become copper atoms

172
Q

What steps are required before weighing the copper electrodes?

A

• Clean with emery paper
• Dip into acetone

173
Q

Test for oxygen

A

A glowing splint relights when placed in a test tube

174
Q

Fullerene

A

• Graphene rolled into a tube/sphere
• Giant covalent lattice
• Conducts electricity
• Used as a lubricant or in drug delivery

175
Q

Where are metals found?

A

In rocks in the Earth’s crust

176
Q

What is an ore ?

A

A rock containing metal

177
Q

What are metals called when they are found in their natural form?

A
  • Uncombined or native
  • They are unreactive metals
178
Q

What is distillation?

A

A process used to separate liquids based on their boiling points

179
Q

What are the two types of distillation?

A

• Simple distillation
• Fractional distillation

• Simple distillation can’t separate liquids with similar boiling points whereas fractional distillation can

180
Q

What is chromatography?

A

A method used to separate a mixture of soluble substances

181
Q

Two phases of chromatography

A

• Stationary phase (where the molecules can’t move)

• Mobile phase (where the molecules can move)

182
Q

Difference between the 2 types of distillation

A

Fractional distillation can separate liquids with similar boiling points whereas simple distillation can’t

183
Q

The reactivity of a metal is related to

A

its tendency to form positive ions and react with oxygen

184
Q

Why do we react metals with acid sometimes?

A

They are not reactive enough to react with water

185
Q

What substances are used to determine the reactivity of a metal?

A

• Water
• Acid

186
Q

Metal + Oxygen —>

A

Metal Oxide

187
Q

Metal + Acid —>

A

Salt + Hydrogen

188
Q

Metal + Water —>

A

Metal Hydroxide + Hydrogen

189
Q

What are the products of this reaction and what is it an example of?

Sodium + Iron oxide —>

A

• Sodium oxide + Iron

Example of a:
• Displacement reaction
• Redox reaction

190
Q

Tendency meaning in terms of reactivity

A

How readily a metal forms ions

191
Q

Which metals do not react with water or acid?

A

• Copper
• Silver
• Gold

192
Q

What is a redox reaction?

A

A reaction where one substance is reduced and another is oxidised

193
Q

Metal extraction methods

A

• Heating with carbon
• Electrolysis

194
Q

How is the reactivity series used to determine whether a metal can be heated by carbon?

A

• If a metal is less reactive than carbon it can be extracted using reduction with carbon
• Anything more reactive than carbon requires electrolysis

195
Q

General equation for reduction with carbon

A

Metal oxide + Carbon —> Metal + Carbon dioxide

196
Q

Why is heating by carbon a better option compared to electrolysis?

A

It’s cheaper as it uses less energy

197
Q

Types of bonds and structures

A

• Ionic —> Ionic lattice

• Covalent —> Giant covalent/Polymers/Simple molecules

• Metallic —> Metals (metallic lattice)

198
Q

Graphite characteristics

A

• Each carbon atom has one delocalised electron
• Giant covalent structure
• Conducts electricity
• Soft as only weak IMFs exist between layers
• Acts as lubricant

199
Q

Why can graphite can act as a lubricant?

A

Layers can slide over each other due to the weak forces between them

200
Q

Diamond characteristics

A

• Giant covalent lattice
• Doesn’t conduct electricity as it has no free electrons
• Very hard
• Used in drill bits or jewellery

201
Q

How did Mendeleev order the periodic table?

A

• He ordered it by atomic mass
• He grouped elements with other ones with similar properties
• He left gaps for elements that haven’t been discovered yet

202
Q

Why did Mendeleev swap some elements round?

A

• Ordering by atomic mass didn’t fit the pattern
• Some of the atomic masses he used were wrong due to the presence of isotopes

203
Q

Difference between the melting point of a pure substance and impure substance

A

Pure substances have 1 melting point whereas impure substances have a range of melting points

204
Q

What is a life cycle assessment?

A

An assessment that calculates the environmental impact of the stages in a product’s life

205
Q

Key processes in a product’s life cycle

A

• Extracting and processing raw materials
• Manufacturing and packaging
• Using and reusing
• Disposing
• (including transport and distribution at each stage)

206
Q

Benefits of recycling

A

• Natural reserves of metal ores will last longer
• Minimises noise and dust pollution caused by mining
• Less energy is required than mining
• No habitat destruction
• Provides job opportunities

207
Q

Disadvantages of recycling

A

• It can be more expensive & more energy demanding to recycle than to extract new metal

• Costs and energy are involved with collecting, sorting and transporting metals

208
Q

High grade ore definition

A

Rock that contains a high percentage of metal

209
Q

Low grade ore definition

A

Rock that contains a low percentage of metal

210
Q

Why do we need alternative metal extraction methods?

A

High grade ores have run out so we need alternative methods of extracting metals from low grade ores

211
Q

Alternative metal extraction methods

A

• Phytomining
• Bioleaching

212
Q

How is phytomining carried out?

A

• Plants are used to absorb metal compounds from low grade ore soil
• These accumulate in the plant’s shoots
• Plants are harvested then burned
• Metal compounds are concentrated in solution
• Metal compounds are extracted from the ash

213
Q

What does bioleaching involve?

A

Bacteria feeding on low grade ores to produce a solution of copper ions (leachate)

214
Q

Advantages of bioleaching

A

• Doesn’t require high temperatures
• No harmful gases like sulfur dioxide is produced
• Causes less damage to landscape than mining
• Conserves supplies of higher grade ores

215
Q

Disadvantages of bioleaching

A

• It’s very slow
• Toxic substances and acid can be produced during the process damaging the environment

216
Q

Advantages of phytomining

A

• It can extract metals from contaminated soils
• No harmful gases like sulfur dioxide is produced
• Causes less damage to landscape than mining
• Conserves supplies of higher grade ores

217
Q

Disadvantages of phytomining

A

• It’s very slow
• It’s more expensive than some mining ores
• Growing plants is dependent on weather conditions

218
Q

How is ammonia produced?

A

• Using the Haber process where:
• Temperature = 450°C
• Pressure = 200 atm (atmospheres)
• Catalyst = Iron

219
Q

What is ammonia mainly used for?

A

Making fertiliser

220
Q

What is the balanced symbol equation for ammonia production

A

N2 + (3)H2 ⇌ (2)NH3

221
Q

How is nitrogen obtained?

A

In the air

222
Q

How is hydrogen obtained?

A

Natural gas

223
Q

Dynamic equilibrium meaning

A

The forward and backward reactions are both happening at the same rate (reversible reactions)

224
Q

What does a simple cell consist of?

A

• 2 electrodes made of metals with different reactivities
• An electrolyte (salt solution/ acid)
(typically KOH)

225
Q

What is a fuel cell?

A

• A cell that produces electrical energy using a reaction between a fuel (often H2) and oxygen
• Water is the only product

226
Q

What are the negative and positive electrodes in a chemical cell?

A

• Anode = negative electrode
• Cathode = positive electrode

227
Q

Why does the voltage reduce over time in a fuel cell?

A

The reactants in the chemical reaction get used up meaning voltage eventually reaches 0V

228
Q

Half equation for oxidation at the anode in a chemical cell

A

(2)H2 → (4)H+ + (4)e-

229
Q

Half equation for reduction at the cathode in a chemical cell

A

O2 + (4)H+ + (4)e- —> (2)H2O

230
Q

How do fuel cells work?

A

As fuel enters the cell it becomes oxidised which sets up a potential difference across the wire

GCSEs (21 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions