Question
Some elements are shown in the order they appear in the reactivity series. The most reactive element is at the top.
sodium
calcium
magnesium
aluminium
zinc
iron
hydrogen
copper
(a) Answer the questions using the list of elements. Each element may be used once, more than
once or not at all.
Identify:
(i) a non-metal
(ii) a metal which is stored under oil
(iii) the main component of steel
(iv) a metal with three electrons in the outer shell of its atoms
(v) a metal found in brass
(vi) a metal that forms chlorides of the type \(XCl_2\) and \(XCl_3\).
(b) Name the main ores of:
(i) zinc ……………………………………………………………………………………………………………….
(ii) aluminium. ……………………………………………………………………………………………………..
(c) In an experiment, a sample of aluminium appeared less reactive than expected.
Explain why.
(d) Name two metals from the list which are extracted by reduction of their ores using carbon.
1 ……………………………………………………………………………………………………………………………….
2 ……………………………………………………………………………………………………………………………….
(e) When zinc granules are added to aqueous copper(II) sulfate, a reaction occurs. During the
reaction, a red-pink solid is formed and the solution becomes colourless.
(i) Name the red-pink solid.
(ii) Name the colourless solution.
(iii) Explain, in terms of particles, why the rate of this reaction increases when the temperature
is increased.
(iv) Suggest two other ways of increasing the rate of this reaction.
1 …………………………………………………………………………………………………………………………
2 …………………………………………………………………………………………………………………………
Answer/Explanation
Answer:
(a) (i) hydrogen
(ii) sodium
(iii) iron
(iv) aluminium
(v) zinc or copper
(vi) iron
(b) (i) zinc blende
(ii) bauxite
(c) protective oxide layer
(d) Any 2 from 3
• zinc
• iron
• copper
(e) (i) copper
(ii) zinc sulfate
(iii)
M1 particles have more energy
M2 More collisions (between particles) occur per second / per unit time
M3 A greater percentage / proportion / fraction of collisions (of particles) are successful / have energy above activation
energy / have energy equal to activation energy
(iv) Any 2 from 3:
• use a catalyst
• use smaller granules
• increase concentration
Question
This question is about copper and its compounds.
(a) Copper has two different naturally occurring atoms, \(^{63}Cu\) and \(^{65}Cu\).
(i) State the term used for atoms of the same element with different nucleon numbers.
(ii) The atomic number of copper is 29.
Complete the table to show the number of protons, neutrons and electrons in the particles
of copper shown.
(iii) Relative atomic mass is the average mass of naturally occurring atoms of an element.
The percentage of the naturally occurring atoms in a sample of copper is shown.
Deduce the relative atomic mass of copper in this sample.
Give your answer to one decimal place.
relative atomic mass = …………………………
(b) Anhydrous copper(II) sulfate is used to test for the presence of water. When this test is positive,
hydrated copper(II) sulfate is formed.
(i) State the colour change seen during this test.
from ……………………………………………………. to ……………………………………………………
(ii) Complete the chemical equation to show the reaction that takes place.
\(CuSO_4 + …………………… \leftrightarrow CuSO_4•5H_2O\)
(iii) State how hydrated copper(II) sulfate can be turned back into anhydrous copper(II) sulfate.
(iv) Describe a test for pure water.
(c) Aqueous copper(II) sulfate contains \(Cu^{2+}\)(aq) ions.
(i) Describe what is seen when aqueous copper(II) sulfate is added to aqueous
sodium hydroxide, NaOH(aq).
(ii) Write the ionic equation for the reaction between aqueous copper(II) sulfate and aqueous
sodium hydroxide.
Include state symbols.
(d) When solid copper(II) nitrate is heated copper(II) oxide, nitrogen dioxide and oxygen are
formed.
\(2Cu(NO_3)_2 → 2CuO + 4NO_2 + O_2\)
Calculate the volume of nitrogen dioxide formed at room temperature and pressure when 4.7g
of \(Cu(NO_3)_2\) is heated.
Use the following steps:
● calculate the mass of one mole of \(Cu(NO_3)_2\)
………………………… g
● calculate the number of moles of \(Cu(NO_3)_2\) used
………………………… moles
● determine the number of moles of nitrogen dioxide formed
………………………… moles
● calculate the volume of nitrogen dioxide formed at room temperature and pressure.
………………………… \(dm^3\)
(e) Write the chemical equation to show the action of heat on sodium nitrate, \(NaNO_3\).
Answer/Explanation
Answer:
(a) (i) isotopes
(ii) 1 mark for each correct row
(iii) M1 = (70 × 63) + (30 × 65) or [ ( 4410) + (1950) ] or 6360 (1)
M2 = M1 / 100 = 63.6 (1)
OR
M1= (0.7(0) × 63) + (0.3(0) × 65) or [ (44.1(0) ) + (19.5(0)) ] (1)
M2 = 63.6 (1)
(b) (i) M1 white (1)
M2 to (light) blue (1)
(ii) \(5H_2O\)
(iii) heating
(iv) M1 boiling point (1)
M2 is 100 °C
OR
M1 freezing point (1)
M2 is 0 °C (1)
(c) (i) blue precipitate
(ii) Alternative suggestion:
M1 \(Cu(OH)_2\) (as only product) (1)
M2 \(Cu^{2+}\) and 2OH– (as reactants) (1)
M3 state symbols (1)
(d) M1 188
M2 4.7 / 188 = 0.025(0)
M3 0.025(0) × 2 = 0.05(0)
M4 0.05(0) × 24.0 = 1.2
(e) \(2NaNO_3 → 2NaNO_2 + O_2\)
\(NaNO_2\) (1)
rest of equation (1)
Question
This question is about electrolysis.
Concentrated hydrochloric acid is electrolysed using the apparatus shown.
(a) Chloride ions are discharged at the anode.
(i) Complete the ionic half-equation for this reaction.
……….Cl– (aq) → ……….(g) + ……….e–
(ii) State whether oxidation or reduction takes place. Explain your answer.
(b) Describe what is seen at the cathode.
(c) Write the ionic half-equation for the reaction at the cathode.
(d) The pH of the electrolyte is measured throughout the experiment.
(i) Suggest the pH of the electrolyte at the beginning of the experiment.
(ii) State how the pH changes, if at all, during the experiment.
Explain your answer.
(e) The electrolysis is repeated using molten lead(II) bromide.
Describe what is seen at the:
● cathode ……………………………………………………………………………………………………………….
● anode. …………………………………………………………………………………………………………………
(f) State two properties of graphite (carbon) which make it suitable for use as an electrode.
1 ……………………………………………………………………………………………………………………………….
2 ……………………………………………………………………………………………………………………………….
Answer/Explanation
Answer:
(a) (i) \(2Cl^– → Cl_2 + 2e^–\)
\(Cl_2\) (1)
rest of equation (1)
(ii) Oxidation AND lose electrons
(b) effervescence (of colourless gas)
(c) \(2H^+ + 2e^– → H_2\)
\(H^+ + e\) as only species on LHS (1)
rest of equation fully correct (1)
(d) (i) 1
(ii) M1 increase (1)
M2 H+ ions being removed (1)
(e) M1 cathode: silver / grey solid (1)
M2 anode: bubbles of orange / brown gas (1)
(f) M1 inert (1)
M2 conducts electricity (1)
Question
Chalcopyrite, \(FeCuS_2\), is used in the manufacture of sulfuric acid in the Contact process.
(a) In the first stage of the process, chalcopyrite reacts with oxygen in the air to produce
sulfur dioxide, \(SO_2\), iron(III) oxide and copper(II) oxide.
Complete the chemical equation for the reaction of \(FeCuS_2\) with oxygen.
\(4FeCuS_2 + 13O_2\) → …………….. + …………….. + ……………..
(b) Sulfur dioxide is then converted to sulfur trioxide.
\(2SO_2 + O_2 \leftrightarrow 2SO_3\)
The reaction is exothermic. It is also an equilibrium.
(i) State two features of an equilibrium.
1 …………………………………………………………………………………………………………………………
2 …………………………………………………………………………………………………………………………
(ii) State the temperature and pressure used in this reaction.
Include units.
● temperature …………………………………………………………………………………………………..
● pressure ………………………………………………………………………………………………………..
(iii) Name the catalyst used.
(iv) Explain why a catalyst is used.
(v) Describe and explain, in terms of equilibrium, what happens when the temperature is
increased.
(c) Concentrated sulfuric acid is a dehydrating agent.
When glucose is dehydrated, carbon and one other product are formed.
Complete the equation to show the dehydration of glucose, \(C_6H_{12}O_6\).
\(C_6H_{12}O_6\) → ………..C + …………………
Answer/Explanation
Answer:
(a) \((4FeCuS 13O_2) → 2Fe_2O_3 + 4CuO + 8SO_2\)
\(Fe_2O_3\) and CuO as a product (1)
Equation fully correct (1)
(b) (i) M1 rate of forward reaction = rate of reverse reaction (1)
M2 concentration of reactants and products are constant (1)
(ii) M1 450 °C (1)
M2 1-2 atm (1)
(iii) vanadium(V) oxide
(iv) increase rate of reaction
(v) M1 equilibrium shifts to left hand side (1)
M2 forward reaction is exothermic (1)
(c) \(C_6H_{12}O_6 → 6C + 6H_2O\)
\(H_2O\) (1)
balance (1)
Question
Alkenes and carboxylic acids are both families of similar compounds with similar chemical properties.
Alkenes and carboxylic acids have different reactions.
(a) State the term used for a ‘family’ of similar compounds.
(b) State the general formula of alkenes.
(c) The structure of but-2-ene is shown.
(i) But-2-ene reacts with aqueous bromine in an addition reaction.
Describe the colour change seen when but-2-ene is added to aqueous bromine.
from ……………………………………………………. to ……………………………………………………
(ii) State what is meant by the term addition reaction.
(iii) Write the chemical equation for the reaction between but-2-ene and bromine.
(iv) But-2-ene forms a polymer.
Suggest the name of the polymer formed from but-2-ene.
(v) Name and draw a structural isomer of but-2-ene.
Show all of the atoms and all of the bonds.
name …………………………………………………………………………………………………………………..
structure
(d) Butanoic acid, \(CH_3CH_2CH_2COOH\), is a carboxylic acid.
(i) Deduce the empirical formula of butanoic acid.
(ii) Complete the chemical equation for the reaction of butanoic acid and sodium carbonate,
\(Na_2CO_3\).
\(2CH_3CH_2CH_2COOH + Na_2CO_3\) → ……………………………… + …………… + ……………
(iii) Butanoic acid reacts with methanol to form an organic compound and water.
● Name the organic compound formed.
● Draw the structure of the organic compound formed.
Show all of the atoms and all of the bonds.
Answer/Explanation
Answer:
(a) homologous series
(b) \(C_nH_{2n}\)
(c) (i) orange to colourless
(ii) (only) one product is formed
(iii) \(C_4H_8 + Br_2 → C_4H_8Br_2\)
\(C_4H_8Br_2\) (1)
equation fully correct (1)
(iv) (poly) but-2-ene
(v) but-1-ene (1)
structure of but-1-ene
(d) (i) \(C_2H_4O\)
(ii) \(2C_3H_7COOH + Na_2CO_3 → 2C_3H_7COONa + H_2O + CO_2\)
\(C_3H_7COONa\) (1)
equation fully correct (1)
(iii) methyl butanoate (1)
ester link (1)
rest of structure (1)