Question
Ethene can be oxidised to form epoxyethane, \( C_{2}H_{4}O. \)
\(C_{2}H_{4}(g)~+~\frac{1}{2}O_{2}(g)\rightleftharpoons C_{2}H_{4}(g)~~~\Delta ^{\theta}=107kJ~mol^{-1}\)
Which set of conditions gives the greatest yield of epoxyethane at equilibrium?
▶️Answer/Explanation
Ans:A
Question
Cobalt can form the positive ion \(Co(NH_{3})_{4}Cl_{2}^{~*}\)
What is the oxidation number of cobalt in this ion?
A +1 B +2 C +3 D +6
▶️Answer/Explanation
Ans:C
Question
When considering one molecule of ethene, which row describes both the hybridisation of the atomic orbitals in the carbon atoms and the overall bonding
▶️Answer/Explanation
Ans:B
Question
\(10cm^{3}\) of ethane is burned in \(45cm_{3}\) of oxygen at a pressure of 101kPa and a temperature of 200 °C. Complete combustion takes place.
What is the total volume of gas present when the reaction is complete, measured under the same conditions?
A \(30cm^{3}\) B \(50cm^{3}\) C \(55cm^{3}\) D \(60cm^{3}\)
▶️Answer/Explanation
Ans:D
Question
Two reactions are shown.
\(H_{2}(g)\rightarrow 2H(g)\)
\(CO(g)~+~\frac{1}{2}O_{2}(g)\rightarrow CO_{2}(g)\)
If molar amounts are used, how can the two energy changes associated with these reactions be
described?
A enthalpy of atomisation and enthalpy of combustion
B enthalpy of atomisation and enthalpy of formation
C bond energy and enthalpy of combustion
D bond energy and enthalpy of formation
▶️Answer/Explanation
Ans:C
Question
The diagram shows the Boltzmann energy distribution curves for molecules of a sample of a gas at two different temperatures.
Which letter on the axes represents the most probable energy for molecules of the same sample of gas at the lower temperature?
▶️Answer/Explanation
Ans:C
Question
What are the units of \(K_{p}\) for the reaction shown?
\(H_{2}O(g)~+~C(s)\rightleftharpoons H_{2}(g)~+~CO(g)\)
A \(Pa^{-1}\) B Pa C Pa^{2} D no units
▶️Answer/Explanation
Ans:B
Question
In this question you should use changes in oxidation numbers to balance a chemical equation.
Acidified potassium dichromate(VI) solution can oxidise a solution of \(V^{2+}\) ions. The equation for this reaction is shown.
\(aCr_{2}O_{7}^{~2-}~+~bV^{2+}~+~cH^{*}\rightarrow dCr^{3+}+eVO_{3}^{~-}~+~fH_{2}O\)
What is the ratio a :b in the correctly balanced equation?
A 1 : 1 B 1 : 2 C 2 : 1 D 4 : 1
▶️Answer/Explanation
Ans:B
Question
A sample of argon gas has a mass of 0.20 g, at a pressure of 100 000Pa and a temperature of 12 °C
Which volume does the gas occupy?
A \(1.2~x~10^{-4}cm^{3}\)
B \(5.0cm^{3}\)
C \(59cm^{3}\)
D \(119cm^{3}\)
▶️Answer/Explanation
Ans:D
Question
In which pair does each species have the same number of unpaired electrons?
A $\mathrm{A} l$ and $\mathrm{Cu}^{2+}$
B $\mathrm{Ca}$ and $\mathrm{Cr}^{3+}$
C $\mathrm{Ca}$ and $\mathrm{Ni}^{2+}$
D $\mathrm{Fe}^{3+}$ and $\mathrm{O}^{2-}$
▶️Answer/Explanation
Ans:A
Question
A sample of solid ammonium chloride decomposes on heating.
solid ammonium chloride → ammonia gas + hydrogen chloride gas
A total of \(2.4~x~10^{21}\) molecules of gas is formed.
How many hydrogen atoms are present in the gaseous products?
A \(1.2~x~10^{21}\) B \(2.4~x~10^{21}\) C \(4.8~x~10^{21} \) D \( 9.6~x~10^{21}\)
▶️Answer/Explanation
Ans:C
Question
A white powder is a mixture of sodium chloride and sodium iodide. It is dissolved in water in a test-tube. An excess of aqueous silver nitrate is added to the test-tube. A precipitate, X, is observed.
An excess of concentrated ammonia is then added to the test-tube containing X. After the test-tube has been shaken, a precipitate, Y, is observed.
Which statement about X or Y is correct?
A X is a pure white colour.
B X is pure silver iodide.
C Y is pure silver chloride.
D Y is yellow
▶️Answer/Explanation
Ans:D
Question
6.90 g of an ammonium salt is heated with an excess of aqueous sodium hydroxide. The volume
of ammonia produced, measured under room conditions, is \(2.51dm^{3}\)
Which ammonium salt is used?
A ammonium carbonate \(M_{r}=96.0\)
B ammonium chloride \(M_{r}=53.5\)
C ammonium nitrate \(M_{r}=80.0\)
D ammonium sulfate \(M_{r}=132.1\)
▶️Answer/Explanation
Ans:D
Question
An excess of MgO is shaken with water. The resulting mixture is filtered into test-tube P.
An excess of BaO is shaken with water. The resulting mixture is filtered into test-tube Q.
Which oxide reacts more readily with water and which filtrate has the lower pH?
▶️Answer/Explanation
Ans:A
Question
Element Z has a giant structure.
The chloride of Z reacts with water to give a solution with a pH less than 5.
Which pair shows two elements which could be Z?
A aluminium, magnesium
B aluminium, silicon
C phosphorus, magnesium
D phosphorus, silicon
▶️Answer/Explanation
Ans:B
Question
Sodium, aluminium and silicon are three elements in Period 3. Each element forms an oxide.Which row has three correct properties of these oxides?
▶️Answer/Explanation
Ans:D
Question
0.25 g of anhydrous magnesium nitrate is heated strongly until it completely decomposes.
What is the total volume of gas produced, measured under room conditions?
A \(40cm^{3}\) B \(81cm^{3}\) C \(101^{3}\) D \(202^{3}\)
▶️Answer/Explanation
Ans:C
Question
Astatine, At, is below iodine in Group 17 of the Periodic Table.
Which statement is most likely to be correct?
A AgAt(s) reacts with an excess of dilute aqueous ammonia to form a solution of a soluble complex.
B Astatine and KCl(aq) react to form KAt(aq) and chlorine.
C KAt(aq) and dilute sulfuric acid react to form HAt(g).
D NaAt(s) and concentrated sulfuric acid react to form astatine.
▶️Answer/Explanation
Ans:D
Question
What is the order of increasing melting point of the three chlorides shown?
\(CC \imath_{4}~~~~~MgCl_{2}~~~~~PC \imath_{5}\)
▶️Answer/Explanation
Ans:A
Question
The skeletal formula of compound X is shown.
Which row is correct?
▶️Answer/Explanation
Ans:A
Question
Which statement is correct?
A 2,2-dimethylpropanoic acid is an isomer of propyl methanoate.
B 2-methylbutan-2-ol is an isomer of hexan-3-ol.
C 3-methylbutan-2-one is an isomer of pentanal.
D 3,3-dimethylbutan-2-one is an isomer of pentan-3-one.
▶️Answer/Explanation
Ans:C
Question
But-1-ene and but-2-ene are treated separately with cold, dilute acidified manganate(VII) ions.
Four students, W, X, Y and Z, make statements about these alkenes and the diols formed from
them.
W One diol contains two primary alcohol groups.
X One diol contains a primary and a secondary alcohol group.
Y One diol contains two secondary alcohol groups.
Z Both alkenes exhibit cis-trans isomerism
Which two students are correct?
A W and Y B W and Z C X and Y D X and Z
▶️Answer/Explanation
Ans:C
Question
2-bromo-2-methylpentane is a tertiary halogenoalkane.
Which organic products are formed when 2-bromo-2-methylpentane reacts with a hot
concentrated ethanolic solution of sodium hydroxide?
A 2-methylpent-1-ene only
B 2-methylpent-1-ene and 2-methylpent-2-ene
C 2-methylpent-2-ene only
D 2-methylpent-2-ene and 4-methylpent-2-ene
▶️Answer/Explanation
Ans:B
Question
Poly(propene) is an addition polymer.
What are the C–C–C bond angles along its polymer chain?
A They are all 109°.
B Half of them are 109° and half are 120°.
C Half of them are 90° and half are 180°.
D They are all 120°.
▶️Answer/Explanation
Ans:A
Question
An alcohol has the molecular formula \(C_{5}H_{12}O\). It has several isomers.
Which isomer forms a yellow precipitate with alkaline aqueous iodine?
A 2,2-dimethylpropan-1-ol
B 2-methylbutan-2-ol
C 3-methylbutan-2-ol
D pentan-3-o
▶️Answer/Explanation
Ans:C
Question
When compound X is heated under reflux with aqueous sodium hydroxide solution two products
are formed: sodium ethanoate and hexan-1-ol.
What is compound X?
▶️Answer/Explanation
Ans:D
Question
What is the major product Z of the following reaction?
▶️Answer/Explanation
Ans:B
Question
The structure of compound Q is shown.
How many chiral centres are present in a molecule of Q?
A 4 B 5 C 6 D 7
▶️Answer/Explanation
Ans:D
Question
Compound X has the infra-red spectrum shown.
What could be the identity of compound X?
A ethanoic acid
B ethanol
C ethylethanoate
D propanone
▶️Answer/Explanation
Ans:A
Question
Which reaction produces an organic anion with a good yield?
A heating ethanenitrile under reflux with dilute sodium hydroxide
B heating ethanenitrile under reflux with dilute sulfuric acid
C heating ethane with sodium metal
D heating ethanol under reflux with dilute sodium hydroxide
▶️Answer/Explanation
Ans:A
Question
The definitions of many chemical terms can be illustrated by chemical equations.
Which terms can be illustrated by an equation that includes the formation of a positive ion?
1 first ionisation energy
2 heterolytic fission of a covalent bond
3 enthalpy change of atomisation
▶️Answer/Explanation
Ans:B
Question
Which molecules have no overall dipole moment?
1 boron trifluoride
2 methane
3 phosphorus pentafluoride
▶️Answer/Explanation
Ans:A
Question
Carbon exists in several different forms. Two of these forms are buckminsterfullerene and
graphene. Buckminsterfullerene is a fullerene allotrope of carbon.
Which statements about buckminsterfullerene and graphene are correct?
1 Both have delocalised electrons.
2 Buckminsterfullerene has a giant molecular structure.
3 The carbon atoms in graphene form a tetrahedral lattice
▶️Answer/Explanation
Ans:D
Question
Carbon monoxide burns readily in oxygen to form carbon dioxide.
What does this information suggest?
1 The +4 oxidation state of carbon is more stable than the +2 state.
2 The standard enthalpy change of formation of carbon dioxide is more negative than the
standard enthalpy change of formation of carbon monoxide.
3 The value of the equilibrium constant for the reaction, \(2CO(g)~+~O_{2}(g)\rightleftharpoons 2CO_{2}(g)\), is likely to be high.
▶️Answer/Explanation
Ans:A
Question
The catalytic converters fitted to cars remove pollutants from the exhaust gases. Some of the
reactions that occur involve oxygen, which comes from the air.
Which pollutants in the exhaust gases will react with oxygen on the surface of the catalytic
converter?
A NO_{2}
B unburnt fuel
C CO
▶️Answer/Explanation
Ans:C
Question
Chlorine reacts with sodium hydroxide in two different ways depending upon the temperature.
reaction 1 \(~~~C\imath_{2}~+~2OH\rightarrow C \imath^{-}~+~C \imath O^{-} ~+~H_{2}O\)
reaction 2 ~~~3C \imath_{2}~+~6OH^{-}\rightarrow 5C \imath ~+~C \imath O_{3}^{~-}~+~3H_{2}O
Which statements about these reactions are correct?
1 Reaction 2 requires a higher temperature than reaction 1.
2 The products of reaction 1 show chlorine in two different oxidation states.
3 The products of reaction 2 show oxygen in two different oxidation states.
▶️Answer/Explanation
Ans:B
Question
In which of the reactions is the organic compound oxidised by the given reagent?
1 \(CH_{3}CHO~+~HCN~regeant\)
2 \(CH_{3}CH_{2}CH_{2}CHO~+~Tollen’s~regeant\)
3 \(CH_{3}CH_{2}CH_{2}CHO~+~Fehling’s~regeant\)
▶️Answer/Explanation
Ans:C
Question
When the apparatus is set up as shown, an orange precipitate forms in test-tube Z
What could compound Q be?
1 \(CH_{3}CH_{2}CH_{2}OH\)
2 \(CH_{3}CH(OH)CH_{3}\)
3 \((CH_{3})_{3}COH\)
▶️Answer/Explanation
Ans:B
Question
Chlorofluoroalkanes that diffuse into the stratosphere are broken down by ultraviolet radiation.
Radicals are generated that cause depletion of ozone.
What are these radicals?
1 chlorine radicals
2 fluorine radicals
3 alkyl radicals
▶️Answer/Explanation
Ans:D
Question
A mixture of the three isomers of \(C_{2}H_{2}C \imath_{2}\) is polymerised.
Which sequences will be seen within the polymer chains?
▶️Answer/Explanation
Ans:A