Question
(a) A list of compounds is shown.
aluminium oxide
calcium bromide
calcium oxide
ethane
ethene
hydrogen chloride
methane
nitrogen dioxide
potassium iodide
potassium manganate(VII)
sodium chloride
Answer the following questions using only the compounds in the list.
Each compound may be used once, more than once or not at all.
Which compound:
(i) when in acidified solution, is used to test for sulfur dioxide
(ii) is the main constituent of natural gas
(iii) when dissolved in water, gives a yellow precipitate on addition of acidified aqueous silver nitrate
(iv) is used in flue gas desulfurisation to neutralise acidic gases
(v) is a reactant used in the manufacture of ethanol?
(b) What is the meaning of the term compound?
(c) Complete the electronic structure of a molecule of hydrogen chloride. Show only the outer shell electrons.
Answer/Explanation
Answer:
(a) (i) potassium manganate(VII)
(ii) methane
(iii) potassium iodide / iodide
(iv) calcium oxide
(v) ehtene
(b) (substance containing) atoms / ions of two or more (different)
elements (1)
(atoms) bonded / chemically combined (1)
(c) pair of bonding electrons between H and Cl (1)
3 non-bonding pairs on Cl and no non-bonding electrons on H / 6 non-bonding electrons on Cl and no non-bonding
electrons on H (1)
Question
Iron is extracted by heating a mixture of coke (carbon), limestone and iron ore in air in a blast furnace.
A diagram of the blast furnace is shown.
(a) Name the ore of iron added to the blast furnace.
(b) The impurities in the iron ore are removed as slag.
(i) What information in the diagram shows that slag is less dense than molten iron?
(ii) Which one of the substances added to the blast furnace helps to remove the impurities?
Explain how it does this.
substance ……………………………………………………………………………………………………………
explanation ………………………………………………………………………………………………………….
(c) Hot air is blown into the blast furnace.
Explain why.
(d) The chemical equation for one of the reactions in the blast furnace is shown.
\(Fe_2O_3 + 3CO → 2Fe + 3CO_2\)
(i) How does this equation show that \(Fe_2O_3\) has been reduced?
(ii) When 16.0g of \(Fe_2O_3\) react with excess carbon monoxide, 11.2g of iron are produced.
Calculate the mass of iron produced when 4.0g of \(Fe_2O_3\) reactwith excess carbon monoxide.
mass of iron = ………………………… g
(e) An isotope of iron is shown.
\(^{58}_{26} Fe\)
Deduce the number of electrons, protons and neutrons in an atom of this isotope of iron.
number of electrons Ans…………………………………………………………………………………………………….
number of protons ………………………………………………………………………………………………………
number of neutrons …………………………………………………………………………………………………….
(f) Iron is a transition element.
Which two of these statements about iron are correct?
Tick two boxes.
Answer/Explanation
Answer:
(a) hematite
(b) (i) slag floats on iron / slag is above the iron ORA
(ii)
limestone (1)
AND 1 mark each for any 2 of:
• it decomposes / it breaks down
• forms calcium oxide / forms CaO
• reacts with impurities / reacts with silicon dioxide / reacts with silicates / reacts with silica / reacts with \(SiO_2\)
(c) to form carbon monoxide / to burn the coke / to burn the carbon
(d) (i) oxygen removed from \(Fe_2O_3\) / iron oxide loses oxygen
(ii) 2.8 (g)
(e) electrons: 26 (1)
protons: 26 (1)
neutrons: 32 (1)
(f) first box down ticked (iron forms coloured compounds) (1)
second box down ticked (iron can act as a catalyst) (1)
Question
Water is essential for many industrial processes.
(a) State one use of water in industry.
(b) What is the pH of pure water?
Draw a circle around the correct answer.
pH 0 pH 6 pH 7 pH 14
(c) Filtration and chlorination are two of the steps used in water treatment.
Describe the purpose of each of these steps.
filtration ……………………………………………………………………………………………………………………..
chlorination ………………………………………………………………………………………………………………..
(d) The changes of state of water are shown.
Give the names of the changes of state represented by A and B.
A ………………………………………………………………………………………………………………………………
B ………………………………………………………………………………………………………………………………
(e) The table compares the reactions of four metals with both steam and dilute hydrochloric acid.
Put the four metals in order of their reactivity.
Put the least reactive metal first.
Answer/Explanation
Answer:
(a) coolant / cooling / solvent / for dissolving
(b) pH 7
(c) filtration: to remove solids / to remove insoluble materials / to separate solids from liquids (1)
chlorination: to kill bacteria / to disinfect (the water) / to kill (harmful) microorganisms (1)
(d) A: melting / fusion (1)
B: condensing / condensation (1)
(e) copper <nickel <zinc <magnesium (2)
if two marks not scored one mark for one consecutive pair reversed / all reversed
Question
Angelic acid and ethanoic acid are both carboxylic acids.
The structure of angelic acid is shown.
(a) (i) On the structure of angelic acid, draw a circle around the functional group that shows that it is a carboxylic acid.
(ii) Deduce the formula of angelic acid to show the number of carbon, hydrogen and oxygen atoms.
(iii) Angelic acid is an unsaturated compound.
Describe a chemical test to distinguish between an unsaturated and a saturated compound.
test ……………………………………………………………………………………………………………………..
result with unsaturated compound …………………………………………………………………………..
result with saturated compound ………………………………………………………………………………
(b) The formula of ethanoic acid is \(C_2H_4O_2\).
Complete the table to calculate the relative molecular mass of ethanoic acid.
Use the Periodic Table to help you.
relative molecular mass = …………………………
(c) Ethanoic acid can be reduced to ethanol.
Complete the structure of ethanol to show all of the atoms and all of the bonds.
(d) Ethanol can be manufactured by fermentation.
Describe the process of fermentation to include:
● the names of the reactants and catalyst
● the conditions required
● the name of the process used to separate the ethanol from the rest of the reaction mixture.
Answer/Explanation
Answer:
(a) (i) circle round COOH group
(ii) \(C_5H_8O_2\)
(iii) aqueous bromine / bromine water / bromine (1)
unsaturated: decolourises / goes colourless / loses its colour (1)
saturated: remains red-brown / remains brown / remains orange / no change (in colour) (1)
(b) 60 (2)
if two marks not scored, one mark for (4 × 1) = 4 OR (2 ×16) = 32
(c) 
(d) 1 mark each for any two of:
• glucose / sugar
• in aqueous solution / in water
• yeast / enzymes / zymase
1 mark each for any two of:
• no oxygen / no air / anaerobic
• pH neutral
• room temperature / stated temperature between 5°C and 40°C (inclusive)
1 mark for:
• (fractional) distillation
Question
The table shows some properties of four metals in Group I of the Periodic Table.
(a) Complete the table to estimate:
● the melting point of rubidium
● the relative electrical conductivity of sodium.
(b) What is the physical state of caesium at 20°C?
Give a reason for your answer.
(c) Describe the trend in the boiling points of the Group I metals.
(d) When potassium reacts with water, a coloured flame is seen and a gas is produced that pops
(i) Complete the chemical equation for this reaction.
\(……K + 2H_2O → 2KOH + ………….\)
(ii) State the colour of the flame when potassium reacts with water.
(iii) The solution formed is alkaline.
Describe how you can use universal indicator solution to determine the pH of the solution.
Answer/Explanation
Answer:
(a) melting point of Rb: any values between 31 °C and 61 °C (inclusive) (1)
conductivity of sodium: values between 15 and 30 (inclusive) (1)
(b) solid (1)
20°C is lower than the melting point / melting point is higher than 20 °C (1)
(c) decrease down the group / decrease from sodium to caesium / increase up the group / increase from caesium to sodium
(d) (i) 2 (K) (on left) (1)
\(H_2\) (on right) (1)
(ii) lilac
(iii) (add indicator to the solution and) observe colour (of indicator) (1)
compare (colour) with colour chart / compare with pH chart (1)
Question
This question is about the reactions of magnesium with nitric acid.
(a) The equation for the reaction of magnesium with concentrated nitric acid is shown.
\(Mg + 4HNO_3 → Mg(NO_3)_2 + 2NO_2 + 2H_2O\)
(i) The reaction is exothermic.
What is the meaning of the term exothermic?
(ii) Which word best describes the compound Mg(NO3)2?
Draw a circle around the correct answer.
acid base oxide salt
(iii) Oxides of nitrogen are formed when fossil fuels are burned.
What type of chemical reaction occurs when fossil fuels are burned?
Draw a circle around the correct answer.
combustion cracking fermentation neutralisation
(iv) Oxides of nitrogen dissolve in rain water to form acid rain.
State one adverse effect of acid rain on buildings.
(b) When very dilute nitric acid reacts with magnesium powder, hydrogen is produced.
(i) Describe a practical method for investigating the rate of this reaction.
(ii) What effect would each of the following have on the rate of this reaction?
● Larger pieces of magnesium are used instead of magnesium powder.
All other conditions stay the same.
……………………………………………………………………………………………………………………………
● The temperature of the reaction mixture is increased.
All other conditions stay the same.
Answer/Explanation
Answer:
(a) (i) transfers thermal energy to surrounding / transfers heat to surroundings / gives out heat
(ii) salt
(iii) combustion
(iv) (chemical) erosion (of mortar / building materials) / corrodes (iron)
(b) (i) measure volume of gas / measure volume of hydrogen / idea of measuring mass of the reaction mixture (1)
reference to (measurement at certain) time(s) (1)
suitable collection apparatus related to method suggested, e.g. gas syringe / upturned measuring cylinder (over
water) / balance (1)
(ii) large pieces: (rate) decreases / gets slower / slows down (1)
increasing temperature: (rate) increases / gets faster (1)
Question
(a) The electrolysis of dilute sulfuric acid produces gases at both electrodes.
(i) The incomplete apparatus is shown.
Complete the diagram by:
● labelling the anode and cathode
● adding connecting wires
● showing how the gases are collected.
(ii) Name the products formed at each electrode.
positive electrode ………………………………………………………………………………………………….
negative electrode ………………………………………………………………………………………………..
(b) Carbon dioxide is produced when sulfuric acid reacts with sodium carbonate.
Name the two other products which are formed.
……………………………………………………………. and …………………………………………………………….
(c) Describe the test for carbon dioxide.
test ……………………………………………………………………………………………………………………………
observations ………………………………………………………………………………………………………………
(d) Carbon dioxide is a greenhouse gas.
State one effect of greenhouse gases on the environment.
…………………………………………………………………………………………………………………………….
Answer/Explanation
Answer:
(a) (i) anode (left) AND cathode (right) correctly labelled (1)
leads connected correctly to electrodes (1)
test-tubes over both electrodes and dipping into electrolyte (1)
(ii) positive electrode: oxygen / \(O_2\) (1)
negative electrode: hydrogen / \(H_2\) (1)
(b) sodium sulfate (1)
water (1)
(c) limewater (1)
turns milky / turns cloudy / white precipitate (1)
(d) climate change / global warming / effect of global warming, e.g. warmer atmosphere / rise in sea levels / glaciers
melting / ice at poles melting / desertification / more extreme weather / climate change / increased flooding
Question
(a) The structures of four substances C, D, E and F, are shown.
(i) Which one of these substances, C, D, E or F, is a gas at room temperature?
(ii) What type of bonding is present in substance E?
(iii) Which one of these substances, C, D, E or F, is soluble in water?
(iv) Which one of these substances, C, D, E or F, conducts electricity when solid?
(b) The halogens have molecules containing two atoms.
What is the name for molecules containing only two atoms?
(c) The reaction of iodine with hydrogen is shown.
\(I_2 + H_2 \leftrightarrow 2HI\)
What is the meaning of the symbol \(\leftrightarrow\)?
(d) Iodine is formed when chlorine reacts with aqueous potassium iodide.
(i) Complete the chemical equation for this reaction.
\(………. + 2KI → I_2 + …….KCl\)
(ii) When aqueous iodine is mixed with aqueous potassium chloride, there is no reaction.
Suggest, in terms of chemical reactivity, why there is no reaction.
Answer/Explanation
Answer:
(a) (i) F
(ii) ionic
(iii) E
(iv) D
(b) diatomic
(c) reversible reaction / the reaction can go forwards or backwards
(d) (i) \(Cl_2\) (on left) (1)
2 (KCl) (on right) (1)
(ii) chlorine is more reactive than iodine / iodine is less reactive than chlorine