AS & A Level Chemistry - 9701 Paper 1 2022 Winter Zone 2

Why is the first ionisation energy of phosphorus greater than the first ionisation energy of silicon?

Sodium peroxide, $\text{Na}_2\text{O}_2$, is used to absorb carbon dioxide from the atmosphere and release oxygen in closed environments such as space capsules and submarines. $$2\text{Na}_2\text{O}_2 + 2\text{CO}_2 \rightarrow 2\text{Na}_2\text{CO}_3 + \text{O}_2$$
Which mass of sodium peroxide would be required to remove $2.4\text{dm}^3$ of carbon dioxide from the atmosphere at room temperature and pressure?

In which species are the numbers of protons, neutrons and electrons all different?

Calcium oxide and magnesium sulfide each react with acid.
$$\text{CaO(s) + 2H⁺(aq) } \rightarrow \text{ Ca²⁺(aq) + H₂O(l)}$$
$$\text{MgS(s) + 2H⁺(aq) } \rightarrow \text{ Mg²⁺(aq) + H₂S(g)}$$
A mixture of these two compounds, X, reacts with exactly 0.125 mol of dilute hydrochloric acid.
The amount of hydrogen sulfide formed is 0.0250 mol.
What was the mass of calcium oxide in mixture X?

Two moles of $VO_2^+$ ions react with one mole of zinc atoms in the presence of dilute acid. The products include $Zn^{2+}$ ions and an ion, Y. Ion Y contains vanadium. Only zinc and vanadium change oxidation state in the reaction.
What is ion Y?

The compound potassium bismuthate(V), KBiO3, is a powerful oxidising agent.
What is the significance of the (V) in potassium bismuthate(V)?

Hydrogen peroxide decomposes slowly at 20°C to form water and oxygen.

$2\text{H}_2\text{O}_2 \rightleftharpoons 2\text{H}_2\text{O} + \text{O}_2$ equilibrium constant = $K_c$

The reaction is faster when a catalyst is present.

Which statement is correct?

A dimer, \\(Q\\), is stable when solid but a dynamic equilibrium is set up in solution.
\\[Q(aq) \rightleftharpoons 2R(aq)\]
A solution of \\(Q\\) has an initial concentration of 0.50 \\text{mol dm}^{-3}\\). When equilibrium has been reached, [Q(aq)] has fallen to 0.25 \\text{mol dm}^{-3}\\).
The changes in [Q(aq)] and [R(aq)] are plotted against time until equilibrium is reached. The value of \\(K_c\\) is then calculated.
Which graph and value for \\(K_c\\) are correct?

The reaction pathway for the forward reaction of a reversible reaction is shown.
Which statement is correct?

The enthalpy changes for the possible reactions W, X, Y and Z are given.
W \(\text{NaOH(aq) + HCl(aq) \to NaCl(aq) + H_2O(l)}\) \(\Delta H^\circ = -56 \text{kJ mol}^{-1}\)
X \(\text{NaCl(aq) + H_2O(l) \to NaOH(aq) + HCl(aq)}\) \(\Delta H^\circ = +56 \text{kJ mol}^{-1}\)
Y \(\text{2HI(g) \to H}_2\text{(g) + I}_2\text{(g)}\) \(\Delta H^\circ = +11 \text{kJ mol}^{-1}\)
Z \(\text{H}_2\text{(g) + I}_2\text{(g) \to 2HI(g)}\) \(\Delta H^\circ = -11 \text{kJ mol}^{-1}\)
Which statement about the activation energies of these reactions is correct?

The Haber process is carried out with a nitrogen partial pressure of 50 kPa, a hydrogen partial pressure of 150 kPa, a temperature of 400 \(^\circ\text{C}\) and an iron catalyst.
$$\text{N}_2(g) + 3\text{H}_2(g) \rightleftharpoons 2\text{NH}_3(g)$$
If all other conditions are kept the same, which change will result in a raised activation energy?

The compound $(CH_3)_3AlCl_3$ has a simple molecular structure.
Which statement about $(CH_3)_3AlCl_3$ is correct?

VSEPR theory should be used in answering this question.
The dot-and-cross diagram for an ozone, $O_3$, molecule is shown.

What is the predicted bond angle in this molecule?

Each of the substances shown is gaseous.
Which substance is most likely to show ideal behaviour in the conditions shown?
[Table_1]

Which graph represents the variation of pressure $p$ and volume $V$ of a sample of an ideal gas at constant temperature?

Use relevant enthalpy changes from the tables to answer this question.

[Table containing reactions and their ΔH values]

[Table containing bond enthalpies]

Which value can be calculated for the enthalpy change for the following reaction?
$$2C(g) + 6H(g) \rightarrow C_2H_6(g)$$

Element X requires strong heating to react with oxygen.
Element X reacts with chlorine to give a covalently-bonded chloride.
What could be the identity of element X?

The melting points of the Period 3 elements sodium to aluminium are shown in the table.

[Table_1: Melting points of Period 3 elements]

Which factor explains the increase in melting points from sodium to aluminium?

The nitrates of beryllium, calcium, magnesium and strontium all decompose in the same way when heated. When 2.00 g of one of these anhydrous nitrates is decomposed, 1.32 g of gas is produced.
What is the nitrate?

In the diagram, each test-tube W, X, Y and Z contains 25 cm³ of a 0.1 mol dm^–3 solution of a salt.



To test-tubes W and X, 25 cm³ of 0.1 mol dm^–3 NaOH(aq) is added.
To test-tubes Y and Z, 25 cm³ of 0.1 mol dm^–3 H₂SO₄(aq) is added.

In which of test-tubes W and X does the liquid have the higher pH and which of test-tubes Y and Z has the greater mass of precipitate?

What is the oxidation state of the chlorine-containing species that kills bacteria in drinking water?

Compound Q is a white crystalline solid which dissolves easily in water.
When concentrated sulfuric acid is added to a dry sample of Q, steamy white fumes are formed.
When these white fumes are passed into aqueous silver nitrate solution, a white precipitate forms.
This precipitate is soluble in dilute ammonia solution.
What is compound Q?

R is a solid. R fizzes when hydrochloric acid is added.
R reacts with hot aqueous sodium hydroxide, giving off a gas which turns red litmus blue.
What is the formula of R?

Photochemical smog is a type of air pollution produced in urban areas by the effect of sunlight on substances released from vehicle exhausts.
Which mixture of primary pollutants leads to the formation of photochemical smog?

T is an element in Period 3.
The first ionisation energy of T is lower than that of the element with one less proton.
The oxide of T does not react with water.
What is the identity of T?

The structure of tartaric acid is shown.
Which statements about tartaric acid are correct?
1. A molecule of tartaric acid has more than one chiral centre.
2. The molecular formula of tartaric acid is $C_4H_4O_6$.
3. One molecule of tartaric acid produces four hydrogen ions in aqueous solution.

A carboxylic acid, P, has no chain isomers. It reacts with an alcohol, Q, that has only one positional isomer.
What could be the ester formed from a reaction between P and Q?

Which pair includes a hydrocarbon without a chiral centre?

What is the major product formed when compound R is warmed with an excess of HBr?

cis-but-2-ene reacts with cold dilute acidified potassium manganate(VII) solution to give product X.
cis-but-2-ene reacts with hot concentrated acidified potassium manganate(VII) solution to give product Y.
Which row describing the reactions of X and Y is correct?
[Table_1]

For which reaction will the major organic product have the lowest relative molecular mass?

C_4H_9Cl reacts with warm dilute aqueous sodium hydroxide solution.
Which isomer of C_4H_9Cl will form the most stable cation intermediate?

1.0 mol of an organic compound, J, requires 6.0 mol of oxygen for complete combustion.
1.0 mol of J reacts with sodium, producing 0.50 mol of a gas that gives a ‘pop’ with a lighted splint.
J reacts with an excess of hot acidified potassium manganate(VII) to produce an organic compound which gives an orange-red precipitate with 2,4-DNPH reagent.
Which compound is J?

Structural isomerism and stereoisomerism should be considered when answering this question.
3-methylhexan-3-ol reacts with hot concentrated sulfuric acid to form several isomeric compounds with the molecular formula \( \text{C}_7\text{H}_{14} \).

\( \text{3-methylhexan-3-ol} \)


How many isomeric compounds could be formed in this reaction?

The table shows a student’s predictions for the reactions of three compounds.
[Table_1]
Which rows show the correct predictions?

Which mechanism describes the reaction of aldehydes and ketones with HCN + NaCN?

Propyl propanoate can be synthesised in three steps using propanenitrile as the only organic starting material.
In step 1, the nitrile is converted into compound X.
In step 2, compound X is converted into compound Y.
In step 3, compound Y is reacted with more of compound X to give propyl propanoate.

Which reagents are suitable for carrying out step 1 and step 2?

The ester $\text{CH}_3\text{CH}_2\text{CO}_2\text{CH}_3$ is hydrolysed by boiling with aqueous sodium hydroxide. Which compound is one of the products?

Compound V polymerises to form polymer W. A section of polymer W is shown.

What is the correct name of compound V?

A molecule of an organic compound, P, contains three carbon atoms and shows a strong absorption at 1720 cm⁻¹ in its infrared spectrum.
P is reacted with an excess of hot acidified potassium dichromate(VI) forming organic product Q.
Q shows a strong absorption at 1700 cm⁻¹ and a strong, broad absorption centred at 2800 cm⁻¹ in its infrared spectrum.

[Table_1]

What is P?