Danho
ZIMSEC O Level · 4024/2 · N2015

Chemistry Paper 2 November 2015

Questions
30
Total marks
119
Time allowed
120 min
Syllabus code
4024/2

Sit this paper online

Questions
30
Pass mark
18
Sit this paper

Answer every question in the printed order, get marked at the end, then see the answers.

The questions

Question 101

[1 marks]Reactions of copper(II) oxide with acid; displacement and thermal decomposition
A student added black copper(II) oxide powder to nitric acid, forming a blue solution P containing copper(II) ions. Which other substance is present in solution P?
  1. ACopper(II) hydroxide
  2. BCopper(II) nitrate
  3. CCopper(II) oxide
  4. DCopper(II) sulfate

Question 102

[1 marks]Reactions of copper(II) oxide with acid; displacement and thermal decomposition
Write a balanced chemical equation, with state symbols, for the reaction between zinc granules and copper(II) sulfate solution.

Answer this when you sit the paper.

Question 103

[1 marks]Reactions of copper(II) oxide with acid; displacement and thermal decomposition
Write a balanced chemical equation, with state symbols, for the thermal decomposition of calcium carbonate.

Answer this when you sit the paper.

Question 201

[1 marks]Titration mole calculations; properties and industrial source of CO2/SO2
In a titration, 21.50 cm3 of 0.1 mol/dm3 sulphuric acid exactly neutralised a sample of aqueous ammonia. How many moles of sulphuric acid does this 21.50 cm3 sample contain?
  1. A0.0043 mol
  2. B0.0215 mol
  3. C0.00215 mol
  4. D0.000215 mol

Question 202

[1 marks]Titration mole calculations; properties and industrial source of CO2/SO2
25 cm3 of aqueous ammonia was exactly neutralised by 21.50 cm3 of 0.1 mol/dm3 sulphuric acid, according to the equation H2SO4(aq) + 2NH4OH(aq) -> (NH4)2SO4(aq) + 2H2O(aq). Calculate the concentration, in mol/dm3, of the ammonia solution.
  1. A0.0043 mol/dm3
  2. B0.086 mol/dm3
  3. C0.344 mol/dm3
  4. D0.172 mol/dm3

Question 203

[1 marks]Titration mole calculations; properties and industrial source of CO2/SO2
Name the industrial process by which carbon dioxide gas is obtained from air.

Answer this when you sit the paper.

Question 301

[1 marks]Uses and environmental effects of gaseous pollutants; reactivity-series non-reactions
Which gas is used by plants for photosynthesis, is used in fire extinguishers and as dry ice for refrigeration, and contributes to global warming as a pollutant?
  1. ACarbon dioxide
  2. BSulfur dioxide
  3. CCarbon monoxide
  4. DOxygen

Question 302

[1 marks]Uses and environmental effects of gaseous pollutants; reactivity-series non-reactions
Aluminium powder that has been exposed to air does not react when added to a solution of iron(II) sulphate. Why does no reaction take place?
  1. AAluminium is less reactive than iron, so it cannot displace iron from the sulphate
  2. BIron(II) sulphate is insoluble in water, so no ions are free to react
  3. CAluminium reacts too quickly for any reaction to be observed happening
  4. DAluminium forms a protective oxide coating that prevents the reaction from occurring

Question 303

[1 marks]Uses and environmental effects of gaseous pollutants; reactivity-series non-reactions
Zinc oxide is heated in a stream of hydrogen gas, but no reaction takes place. Why?
  1. AZinc is higher up the reactivity series than hydrogen, so hydrogen cannot displace zinc from zinc oxide
  2. BHydrogen is higher up the reactivity series than zinc, so zinc cannot displace hydrogen from zinc oxide
  3. CZinc oxide does not react with gases
  4. DThe experiment was not heated for long enough

Question 401

[1 marks]Ethanol, ethanoic acid and protein hydrolysis
Ethene reacts with reagent X in the presence of a catalyst to form compound P, CH3CH2OH. Name reagent X.
  1. AWater
  2. BEthanoic acid
  3. COxygen
  4. DHydrogen

Question 402

[1 marks]Ethanol, ethanoic acid and protein hydrolysis
Ethanol (compound P, CH3CH2OH) is oxidised by atmospheric oxygen to form compound Q. Name compound Q.

Answer this when you sit the paper.

Question 403

[1 marks]Ethanol, ethanoic acid and protein hydrolysis
Ethene gas and ethanol (compound P) are each shaken separately with bromine water. Which observation would distinguish between them?
  1. AEthene decolourises the bromine water, while ethanol does not
  2. BEthanol decolourises the bromine water, while ethene does not
  3. CBoth ethene and ethanol decolourise the bromine water
  4. DNeither ethene nor ethanol causes any colour change

Question 501

[1 marks]Paper chromatography of inks
A chromatogram of ink samples M, 1, 2 and 3 was developed. Inks M and 2 each produced three dye spots at matching heights, while inks 1 and 3 each produced only one dye spot. How many different dyes are present in ink M?

Answer this when you sit the paper.

Question 502

[1 marks]Paper chromatography of inks
On a developed chromatogram, ink 2 produced spots matching ink M exactly in both number and position, while inks 1 and 3 each produced only a single spot at a different height from ink M's spots. Which sample ink was most likely used to write the message, and why?
  1. AInk 2, because its spots match ink M in both number and position
  2. BInk 1, because it produced only one spot
  3. CInk 3, because it produced only one spot
  4. DInk 1, because its single spot is closest to the solvent front

Question 503

[1 marks]Paper chromatography of inks
In a paper chromatography experiment, the solvent front travelled 8.0 cm and a dye in ink 3 travelled 3.0 cm. Calculate the Rf value of this dye.

Answer this when you sit the paper.

Question 601

[1 marks]Ionic bonding, giant ionic vs molecular structures, electrolysis of copper(II) chloride, electronic structure
Which of the following best defines ionic bonding?
  1. AA bond formed by the transfer of electrons between a metal atom and a non-metal atom, producing oppositely charged ions held together by electrostatic attraction
  2. BA bond formed by a sea of delocalised electrons surrounding positive metal ions
  3. CA weak attractive force between neutral molecules caused by temporary dipoles
  4. DA bond formed by the sharing of a pair of electrons between two non-metal atoms, as seen in simple covalent molecules such as chlorine or water

Question 602

[1 marks]Ionic bonding, giant ionic vs molecular structures, electrolysis of copper(II) chloride, electronic structure
Naphthalene does not conduct electricity, whether solid or molten. Why?
  1. AIt has too high a melting point for ions to move
  2. BIt is a giant ionic lattice with tightly bound ions
  3. CIt has no free (mobile) ions or delocalised electrons to carry charge
  4. DIts molecules carry an overall negative charge that repels current

Question 603

[1 marks]Ionic bonding, giant ionic vs molecular structures, electrolysis of copper(II) chloride, electronic structure
Element X has 9 protons and 10 neutrons. How many electrons are in the outer (valence) shell of a neutral atom of X?

Answer this when you sit the paper.

Question 701

[1 marks]Blast furnace impurities, butenedioic acid reactions, addition polymerisation
Cast iron produced in the blast furnace contains 4 to 5% carbon. Name one other impurity commonly found in cast iron.

Answer this when you sit the paper.

Question 702

[1 marks]Blast furnace impurities, butenedioic acid reactions, addition polymerisation
Butenedioic acid, HOOC-CH=CH-COOH, contains a carbon-carbon double bond. What is observed when aqueous bromine is added to butenedioic acid?
  1. ANo visible change occurs, because the acid is saturated
  2. BA colourless gas is released as bromine reacts with the -COOH groups
  3. CThe bromine water is decolourised as bromine adds across the double bond
  4. DThe bromine water turns from orange to black

Question 703

[1 marks]Blast furnace impurities, butenedioic acid reactions, addition polymerisation
Many ethene molecules, CH2=CH2, join together in an addition reaction to form product N. Name product N.

Answer this when you sit the paper.

Question 801

[1 marks]Preparing pure sodium chloride; identifying ions in a salt; calcium reacting with water
Which procedure correctly describes how a pure sample of sodium chloride can be prepared from solutions of hydrochloric acid and sodium hydroxide of known concentrations?
  1. AMix the acid and alkali, then immediately filter without evaporating
  2. BMix the acid and alkali in the exact mole ratio for neutralisation, then evaporate the resulting solution to concentrate it, cool to crystallise, and filter and dry the crystals
  3. CAdd excess sodium hydroxide to the hydrochloric acid without measuring exact quantities, then attempt to filter off a solid precipitate, even though sodium chloride is soluble and would not form one
  4. DBoil the sodium hydroxide alone until it decomposes into sodium chloride

Question 802

[1 marks]Preparing pure sodium chloride; identifying ions in a salt; calcium reacting with water
A colourless salt solution gives a white precipitate when it is acidified with dilute nitric acid and then treated with aqueous barium nitrate. Which anion is present in the salt?

Answer this when you sit the paper.

Question 803

[1 marks]Preparing pure sodium chloride; identifying ions in a salt; calcium reacting with water
Iodide ions are suspected to be present in a salt solution. Which test and observation would confirm their presence?
  1. AAdd aqueous barium nitrate; a white precipitate forms that is insoluble in dilute acid
  2. BAdd aqueous sodium hydroxide; a white precipitate forms that dissolves in excess
  3. CAcidify the solution with dilute nitric acid, then add silver nitrate solution; a yellow precipitate forms that is insoluble in ammonia
  4. DAdd dilute hydrochloric acid; a colourless gas that turns limewater milky is produced

Question 901

[1 marks]Contact process flow diagram; converting sulphuric acid to ammonium sulphate fertilizer
In the Contact process for manufacturing sulfuric acid, Fig.5's flow diagram shows sulfur and dry air entering box A; the process proceeds A -> B -> C, with oxygen also fed into C; C -> D, with water entering D and concentrated sulfuric acid leaving D; D -> E, with waste gases leaving E. In which box is sulfur dioxide oxidised to sulfur trioxide (the catalytic converter)?
  1. AD
  2. BA
  3. CB
  4. DC

Question 902

[1 marks]Contact process flow diagram; converting sulphuric acid to ammonium sulphate fertilizer
Using the same Fig.5 flow diagram (sulfur and dry air enter box A; A -> B -> C, with oxygen fed into C; C -> D, with water entering D and concentrated sulfuric acid leaving D; D -> E, with waste gases leaving E), which box represents the chimney, where waste gases are released?
  1. AD
  2. BE
  3. CB
  4. DC

Question 903

[1 marks]Contact process flow diagram; converting sulphuric acid to ammonium sulphate fertilizer
In the Contact process, sulfur dioxide is oxidised to sulfur trioxide in the catalytic converter at a temperature of about 450 degrees C. Name the catalyst used in this step.

Answer this when you sit the paper.

Question 1001

[1 marks]Physical/chemical properties of bromine and iodine; displacement of bromine by chlorine; waste-disposal issues
Which statement correctly compares the physical properties of bromine and iodine at room temperature?
  1. ABromine is a solid and iodine is a liquid, with bromine having the higher melting and boiling point, the reverse of the true trend
  2. BBoth bromine and iodine are liquids at room temperature
  3. CBoth bromine and iodine are solids at room temperature
  4. DBromine is a liquid and iodine is a solid, with iodine having the higher melting and boiling point

Question 1002

[1 marks]Physical/chemical properties of bromine and iodine; displacement of bromine by chlorine; waste-disposal issues
Chlorine gas is bubbled through a colourless aqueous solution of potassium bromide, according to the equation 2KBr(aq) + Cl2(g) -> 2KCl(aq) + Br2(g). What colour change is observed in the solution?
  1. AColourless to purple
  2. BColourless to orange
  3. COrange to colourless
  4. DColourless to yellow-green

Question 1003

[1 marks]Physical/chemical properties of bromine and iodine; displacement of bromine by chlorine; waste-disposal issues
Chlorine gas reacts with potassium bromide solution: 2KBr(aq) + Cl2(g) -> 2KCl(aq) + Br2(g). What type of reaction is this?

Answer this when you sit the paper.

More sittings of this paper

The answers, and why they are the answers

Sit the paper here to see which ones you got right. Danho explains every question, keeps your score, and works without a connection.

Get it on Google PlayDownload on the App Store