AS & A Level Chemistry - 9701 Paper 1 2020 Summer Zone 3

Which particle has equal numbers of protons and neutrons and an electronic structure of $1s^2 2s^2 2p^6 3s^2 3p^6$?

Which molecule contains six bonding electrons?

Solid carbon dioxide, CO$_2$, is similar to solid iodine, I$_2$, in its structure.
Which statement about solid CO$_2$ and solid SiO$_2$ is correct?

The enthalpy changes of two reactions are shown.
$ K_2CO_3(s) + 2HCl(aq) \rightarrow 2KCl(aq) + H_2O(l) + CO_2(g) \; \Delta H = -34.0 \, \text{kJ mol}^{-1} $
$ KHCO_3(s) + HCl(aq) \rightarrow KCl(aq) + H_2O(l) + CO_2(g) \; \Delta H = +32.8 \, \text{kJ mol}^{-1} $
What is the enthalpy change for the reaction shown?
$ 2KHCO_3(s) \rightarrow K_2CO_3(s) + H_2O(l) + CO_2(g) $

Nitrogen reacts with oxygen to form nitrogen monoxide, NO, and nitrogen dioxide, NO₂. Nitrogen dioxide reacts with water and with hydroxide ions.

N₂(g) + O₂(g) → 2NO(g)
2NO(g) + O₂(g) → 2NO₂(g)

2NO₂(g) + H₂O(l) → HNO₂(aq) + H⁺(aq) + NO₃⁻(aq)
2NO₂(g) + 2OH⁻(aq) → NO₂⁻(aq) + NO₃⁻(aq) + H₂O(l)

What can be deduced using only the information from these equations?

Which solution has the lowest pH value?

The element sulfur produces a mass spectrum with the following peaks.

[Table_1]

Which relative atomic mass of sulfur can be calculated from these data, given to four significant figures?

What is the electronic configuration of an isolated Ni^{2+} ion?

At 200°C aluminium chloride is a gas with $M_r = 267$.
What is the number of covalent bonds, dative covalent bonds and lone pairs of electrons in one molecule of aluminium chloride at 200°C?
[Table_1]

When solid $KClO_3$ is heated in the absence of air, a mixture of two chlorine compounds in the mole ratio of 3:1 is formed. Chlorine is the only element whose oxidation number changes in this reaction.
What could be the oxidation numbers of chlorine in the two compounds that are formed?

Two reactions are shown.

reaction 1 \( \text{X}_2(g) + \text{Y}_2(g) \rightleftharpoons 2\text{XY}(g) \)

reaction 2 \( \text{XY}(g) \rightleftharpoons \frac{1}{2} \text{X}_2(g) + \frac{1}{2} \text{Y}_2(g) \)

The equilibrium constant, \( K_p \), for reaction 1 is 0.0052.

What is \( K_p \) for reaction 2?

Compound T is a white crystalline solid.
When a sample of compound T is mixed with aqueous sodium hydroxide and heated, a gas is produced which turns damp red litmus paper blue.
Further testing of a solution of compound T with aqueous barium chloride produces a dense white precipitate which does not dissolve when dilute hydrochloric acid is added to the mixture.
What is the identity of compound T?

Which property explains the trend in volatility of the elements going down Group 17?

The statements apply to the elements in Group 2.
Which statement is correct?

Which element, when burned in oxygen, can form an oxide that is a reducing agent?

Nitrogen oxides are removed from the exhaust gases of internal combustion engines by the action of a catalyst in a catalytic converter.
Which row is correct?
[Table_1]

The addition of aqueous silver nitrate to aqueous barium chloride produces a white precipitate which dissolves in an excess of dilute aqueous ammonia to form a colourless solution.
The addition of an excess of dilute nitric acid to the colourless solution produces a white precipitate, Z.
What is Z?

Which property shows an increase from calcium to barium going down Group 2?

Element X is in Period 3. It reacts rapidly with water to form an alkaline solution.
Which statement about the chloride of element X is correct?

Structural and stereoisomerism should be considered when answering this question.
When trans-pent-2-ene reacts with HBr, how many different products can form?

Ester P has the following structural formula.



Which compounds are produced when P is hydrolysed using dilute hydrochloric acid?

There are many non-cyclic alcohols that cannot be oxidised by warm acidified MnO$_4^-$ ions. Alcohol X is the member of this set of alcohols with the lowest molecular mass.
How many moles of oxygen are required for the complete combustion of 1.0 mol of alcohol X?

Butanoic acid can be produced from 1-bromopropane in two steps using reagents V and W as shown.

What could be reagents V and W?

Which statement about compound T and compound U is correct?
[Image_1: Structures of compound T and compound U]

The diagram shows the infrared spectrum of an organic compound.

What could be the identity of this compound?

Which reagent reacts with both of the −OH groups in lactic acid, $CH_3CH(OH)CO_2H$?

1,2-dibromopropane can be made from 1-bromopropane in two steps. Which row is correct? [Table_1]

2-methylbut-2-ene reacts with HBr(g) to form two isomeric products. During the reaction two positively charged intermediates can be made.
Which diagram shows the more stable of the two positively charged intermediates?

The ester ethyl methanoate is prepared in a school laboratory by reacting a carboxylic acid with an alcohol. During the reaction, only 50.0% of the alcohol is converted into the ester. Which mass of alcohol is needed to prepare 10.0 g of the ester?

Compound X has the structure shown.

Which type of carbonyl group is present and how many chiral centres are there in one molecule of X?

Which contain one mole of the underlined substance under room conditions?
1. a balloon containing 24.0 dm$^3$ of \underline{helium}
2. a block of \underline{calcium carbonate} weighing 100.1 g
3. 4000 cm$^3$ of a 0.250 mol dm$^{-3}$ solution of \underline{sulfuric acid}

Buckminsterfullerene is a fullerene allotrope of carbon.
Which statements about buckminsterfullerene are correct?
1. Buckminsterfullerene is a giant covalent molecule.
2. Buckminsterfullerene has delocalised electrons.
3. Buckminsterfullerene has strong intramolecular bonds.

Gaseous sodium ions can be formed from sodium atoms.
Na(s) \rightarrow \text{Na}^+(g)
Which quantities are required to calculate the enthalpy change of formation of \text{Na}^+(g)?
1. first ionisation energy of sodium
2. enthalpy change of atomisation of sodium
3. enthalpy change of formation of sodium

The responses A to D should be selected on the basis of
[Table_1]
No other combination of statements is used as a correct response.

The Haber process is used in industry to form ammonia from hydrogen and nitrogen.
$$3\text{H}_2 + \text{N}_2 \rightleftharpoons 2\text{NH}_3$$
Which statements about the activation energy for this process are correct?

1. The activation energy for the forward reaction is the same as the activation energy for the reverse reaction.
2. The activation energy for the reverse reaction is decreased by the addition of iron.
3. The activation energy is the minimum energy that colliding particles must possess in order to react.

Strontium nitrate is heated strongly for several minutes.
Which statements are correct?
1. A brown gas is produced.
2. A gas is produced that relights a glowing splint.
3. A white powder remains after heating.

When added to water, which oxides will not cause a change in pH?
1. $\text{Al}_2\text{O}_3$
2. $\text{SiO}_2$
3. $\text{P}_4\text{O}_{10}$

Propanal reacts with hydrogen cyanide to form 2-hydroxybutanenitrile. A suitable catalyst for this reaction is sodium cyanide.
$$\text{NaCN}$$
$$\text{CH}_3\text{CH}_2\text{CHO} + \text{HCN} \rightarrow \text{CH}_3\text{CH}_2\text{CH(OH)CN}$$
Which statements about this catalysed reaction of propanal with hydrogen cyanide are correct?
1. The sodium cyanide provides a stronger nucleophile than HCN.
2. The reaction can be classified as nucleophilic substitution.
3. The hydrogen cyanide molecule attacks the propanal molecule to form an intermediate ion.

A reaction mechanism is shown.

Which statements about this reaction are correct?
1. It is a substitution reaction.
2. $OH^- \text{ behaves as a nucleophile.}$
3. Heterolytic bond fission is involved.

On complete combustion, a sample of X produces 44 g of carbon dioxide and 27 g of water.
On complete combustion, a sample of Y produces 44 g of carbon dioxide and 18 g of water.
On complete combustion, a sample of Z produces 22 g of carbon dioxide and 9 g of water.
Which substances could be straight chain alkanes?

Which pairs are structural isomers of each other?
1. $\text{CH}_3\text{CH}_2\text{CH}_2\text{CH}_2\text{CH}_2\text{CO}_2\text{H}$ and $\text{CH}_3\text{CH}_2\text{CH}_2\text{CO}_2\text{CH}_2\text{CH}_3$
2. $\text{CH}_3\text{CH}($ \begin{array}{c} | \end{array} $\text{CH}_3)\text{CH}_2\text{CH}_2\text{CH}_3$ and $\text{CH}_3\text{CH}_2$ \begin{array}{c} | \end{array} $\text{CHCH}_3\text{CH}_2\text{CH}_3$
3. $\text{CH}_3\text{CH}_2\text{CH(OH)CH}_2\text{CH}_3$ and $\text{CH}_3\text{CH}_2\text{CH(OH)CH}_2\text{CH}_2\text{CH}_3$