A Level Chemistry (9701) Past Papers – Cambridge International

HCN has been detected in interstellar gas. The molecules below have also been detected in
interstellar gas.
Which molecule contains the same total number of valence shell (outer shell) electrons as HCN?

Chlorine dioxide, ClO₂, reacts with aqueous sodium hydroxide to produce water and a mixture of
two sodium salts, NaClO₂ and NaClO₃.
What is the mole ratio of NaClO₂ to NaClO₃ in the product mixture?

The ester CH₃CH₂CO₂CH₃ is hydrolysed by boiling with aqueous sodium hydroxide.
Which compound is one of the products?

Hydrogen iodide is added to an evacuated reaction vessel. The vessel is sealed and warmed. A
decomposition reaction occurs. Hydrogen and iodine are formed. Some hydrogen iodide remains.
When equilibrium is established, the total pressure is 1.20 × 10⁵Pa. The partial pressure of hydrogen
is 4.00 × 10³Pa.
Hydrogen iodide, hydrogen and iodine are all gaseous under the conditions used.
What is the value of Kp for the equilibrium at this temperature, assuming the decomposition is the
forward reaction?

Which compound reacts with 2,4-dinitrophenylhydrazine reagent but does not react with Tollens’
reagent?

In Group 2 of the Periodic Table, the properties of the elements and their compounds show regular
change down the group.
Which property shows a decrease from magnesium to barium?

Which compound gives both:

• an orange precipitate with 2,4-DNPH reagent
• and a yellow precipitate with alkaline I2(aq)?

The Contact process takes place at a pressure between 100 000 Pa and 200 000 Pa. A catalyst is
used.
Which statement is correct?

In a catalytic converter, 5.6 g of carbon monoxide react with an excess of nitrogen monoxide.
What is produced in this reaction?

Element X has six more protons than element Y.
Which statement must be correct?

Which statement about the first ionisation energies of magnesium and neon is correct?

Which reaction has a nucleophilic addition mechanism and gives a good yield of product under
the stated conditions?

The equation for a chemical reaction is shown. All substances are in their standard states.
XeF₆ + 3H₂O → XeO₃ + 6HF
Which statement describes the standard enthalpy change of reaction for this reaction?

In which species is there a lone pair of electrons?

A sample of 2.30 g of ethanol is mixed with an excess of aqueous acidified potassium
dichromate(VI). The reaction mixture is boiled under reflux for one hour. The required organic
product is then collected by distillation. The yield of product is 60.0%.
Which mass of product is collected?

Tartaric acid, HOOCCH(OH)CH(OH)COOH, is found in many plants.
A sample of tartaric acid reacts with an excess of LiAlH₄ to form the organic product J.
What happens when NaOH(aq) is added to separate samples of tartaric acid and J?

In this question, alkenes and cyclic alkanes should be considered.
How many structural isomers of C₄H₈ are there?

The oxides BaO, CaO, MgO and SrO all produce alkaline solutions when added to water.
Which oxide produces the saturated solution with the highest pH?

Sodium, magnesium, aluminium, silicon and phosphorus are all elements in Period 3 of the Periodic
Table.
Three statements about the oxides and chlorides of these elements are given.

1. The ionically bonded oxides all react with dilute hydrochloric acid
2. All metal chlorides produce neutral solutions when added to water
3. The two most electronegative elements both form covalently bonded chlorides.

Which statements are correct?

A sample of sulfur consists mostly of ³²S. It also contains 4.2% ³⁴S and 2.8% ³⁶S. No other
isotopes of sulfur are present.

What is the relative atomic mass, Ar, of this sample of sulfur?

Compound Y is heated with a mild oxidising agent. One of the products of the reaction reacts with
hydrogen cyanide forming 2-hydroxybutanenitrile.
What is compound Y?

Which reagent will react with pentan-3-ol to give a mixture of stereoisomers?