Chemistry Paper 2 November 2014

1. A$\frac{p_{N_2}\,p_{H_2}^3}{p_{NH_3}^2}$
2. B$\frac{p_{NH_3}}{p_{N_2}\,p_{H_2}}$
3. C$\frac{2p_{NH_3}}{p_{N_2} + 3p_{H_2}}$
4. D$\frac{p_{NH_3}^2}{p_{N_2}\,p_{H_2}^3}$

1. A0.20, 0.60 and 0.40 mol
2. B1.8, 1.4 and 0.20 mol
3. C1.8, 1.4 and 0.40 mol
4. D1.8, 1.8 and 0.40 mol

1. A0.111
2. B0.200
3. C0.389
4. D0.500

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1. A9.7 atm
2. B0.10 atm
3. C0.42 atm
4. D2.4 atm

1. A298 K, 10 atm and $0.1\ mol\,dm^{-3}$ solutions
2. B373 K, 1 atm and saturated solutions
3. C273 K, 1 atm and $1\ mol\,dm^{-3}$ solutions
4. D298 K, 1 atm and $1\ mol\,dm^{-3}$ solutions

1. A$+0.61\ V$
2. B$+1.21\ V$
3. C$+2.01\ V$
4. D$+2.81\ V$

1. Adecreases, because silver is oxidised
2. Bis unchanged, because ammonia is not an electrolyte
3. Cincreases, because $[Ag^+]$ falls as the complex ion forms
4. Dfalls to zero, because the electrode dissolves

1. Athe concentration of ions present at equilibrium
2. Bthe standard hydrogen electrode
3. Cany reference metal chosen by the experimenter
4. Dthe electrode of highest atomic number in the cell

1. A$2SO_4^{2-} + 2Ag^+ \rightarrow S_2O_8^{2-} + 2Ag$
2. B$S_2O_8^{2-} + 2Ag^+ \rightarrow 2SO_4^{2-} + 2Ag$
3. C$S_2O_8^{2-} + Ag \rightarrow 2SO_4^{2-} + Ag^+$
4. D$S_2O_8^{2-} + 2Ag \rightarrow 2SO_4^{2-} + 2Ag^+$

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1. Ait produces a colourless solution, unlike the silver half cell
2. Bit contains a significantly larger number of atoms and electrons per formula unit
3. Cit has the more positive standard electrode potential, so it is reduced
4. Dsilver is a solid metal, so it cannot be reduced further

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1. Athe decay of nitrate fertilisers
2. Bthe evaporation of sea water
3. Cthe burning of fossil fuels containing sulphur
4. Dthe electrolysis of brine

1. Aa high pressure would destroy the catalyst
2. Bthe reaction is endothermic
3. Ca low pressure gives a higher yield
4. Dthe yield is already high, so high pressure plant is not worth its cost

1. Aabsorbs the sulphur trioxide formed
2. Bprovides an alternative path of lower activation energy
3. Cshifts the equilibrium to the right
4. Dincreases the yield of sulphur trioxide

1. Ait raises the salinity of rivers and lakes
2. Bit displaces oxygen from the atmosphere, causing suffocation
3. Cit dissolves in atmospheric moisture and falls as acid rain
4. Dit depletes the ozone layer by catalytic chain reactions

1. Ableaches away the food's natural colourings
2. Bkills microorganisms and prevents oxidation of the food
3. Craises the internal pH of the food to alkaline levels, slowing enzyme action
4. Dneutralises stomach acid once the food is eaten

1. Acooling speeds up the vanadium(V) oxide catalyst, so it works faster
2. Bcooling condenses the $SO_3$ formed into a liquid, continuously removing it from the gaseous equilibrium mixture as more forms
3. Cthe reaction is endothermic and needs heat removed to keep proceeding
4. Dthe reaction is exothermic, so lowering the temperature shifts the equilibrium towards $SO_3$, raising the yield

1. Adilutes the $SO_2$ so the reaction proceeds more slowly
2. Bincreases the proportion of oxygen present, shifting the equilibrium further towards $SO_3$
3. Cremoves the $SO_3$ formed from the mixture continuously, preventing it decomposing back into $SO_2$ and $O_2$
4. Dacts as an additional catalyst for the oxidation of $SO_2$

1. Aethanolic KCN, heat under reflux
2. Bammonia in ethanol, sealed tube
3. Cconcentrated $H_2SO_4$ at 170 °C
4. Daqueous NaOH, warm

1. Aheating with concentrated HCl
2. Bwarming with aqueous NaOH
3. Crefluxing with acidified $K_2Cr_2O_7$
4. Dreduction with $LiAlH_4$ in dry ether

1. Atwo alkyl groups release electrons to nitrogen, making the lone pair more available
2. Bit has a higher relative molecular mass
3. Cit can form more hydrogen bonds with water
4. Dits nitrogen atom has no lone pair

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1. Aas refrigerants and aerosol propellants
2. Bas reducing agents in the blast furnace
3. Cas catalysts in the Haber process
4. Das fertilisers supplying nitrogen to crops

1. Aare chemically stable and persist in the atmosphere, allowing them to catalytically break down stratospheric ozone
2. Bincrease soil salinity, which reduces crop yields near industrial sites
3. Care highly reactive and burn readily in air, releasing acidic combustion gases that fall as acid rain over wide areas
4. Dbiodegrade rapidly in soil, releasing toxic breakdown products into groundwater

1. Ahydrolyses the amide links in the chain
2. Bdehydrates the polymer
3. Creduces the carbonyl groups
4. Doxidises the polymer chain

1. Aneutralises acidic soils
2. Bhas a high nitrogen content
3. Ckills weeds in the soil
4. Dis insoluble in water

1. Afree radical substitution
2. Belectrophilic addition
3. Celectrophilic substitution
4. Dnucleophilic addition

1. Aa lactone (ester) group and a ketone (carbonyl) group
2. Ban aldehyde group and a primary amine group, both capable of forming hydrogen bonds
3. Ca carboxylic acid group and an amide group
4. Dan alcohol group and a nitrile group

1. Aelectrophilic substitution on its aromatic ring
2. Boxidation of its aromatic side chain to a carboxylic acid under vigorous acidic conditions
3. Chydrolysis of its lactone (ester) group, forming a carboxylate salt and an alcohol
4. Dreduction of its ketone group to a secondary alcohol

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1. Aoxidising any alkyl side chain on the ring to a carboxylic acid
2. Bhydrolysing the ester group attached to the ring
3. Creducing the aromatic ring to a cyclohexane ring
4. Dnitrating the ring to give a nitro-substituted product under fuming nitric acid conditions

1. Aterylene has a much lower relative molecular mass than nylon-6,6, so more of it dissolves directly into the sweat layer during use
2. Bterylene fibres are woven more loosely, letting sweat pass straight through
3. Cnylon's amide groups are far more polar than terylene's ester groups
4. Dits polar ester (C=O) groups form more hydrogen bonds with water than nylon's amide groups, which are largely tied up in intramolecular bonding