AS & A Level Chemistry - 9701 Paper 1 2013 Summer Zone 1

Solutions containing chlorate(I) ions are used as household bleaches and disinfectants. These solutions decompose on heating as shown.
$$3 ext{ClO}^- ightarrow ext{ClO}_3^- + 2 ext{Cl}^-$$
Which oxidation state is shown by chlorine in each of these three ions?

A mixture of 10 cm³ of methane and 10 cm³ of ethane was sparked with an excess of oxygen. After cooling to room temperature, the residual gas was passed through aqueous potassium hydroxide.
All gas volumes were measured at the same temperature and pressure.
What volume of gas was absorbed by the alkali?

The diagram shows an electrolytic cell for the extraction of aluminium.
Which statement is correct?

Use of the Data Booklet is relevant to this question.
The elements radon (Rn), francium (Fr) and radium (Ra) have proton numbers 86, 87 and 88 respectively.
What is the order of their first ionisation energies?
[Table_1]

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

An experiment is set up to measure the rate of hydrolysis of ethyl ethanoate. $$ \text{CH}_3\text{CO}_2\text{C}_2\text{H}_5 + \text{H}_2\text{O} \rightleftharpoons \text{CH}_3\text{CO}_2\text{H} + \text{C}_2\text{H}_5\text{OH} $$ The hydrolysis is found to be slow in neutral aqueous solution but it proceeds at a measurable rate when the solution is acidified with hydrochloric acid.
What is the function of the hydrochloric acid?

The reaction pathway for a reversible reaction is shown below. Which statement is correct?

Why does the rate of a gaseous reaction increase when the pressure is increased at a constant temperature?

Which would behave the least like an ideal gas at room temperature?

The general gas equation can be used to calculate the $M_r$ value of a gas. For a sample of a gas of mass $mg$, which expression will give the value of $M_r$?

A solution of $\text{Sn}^{2+}$ ions will reduce an acidified solution of $\text{MnO}_4^-$ ions to $\text{Mn}^{2+}$ ions. The $\text{Sn}^{2+}$ ions are oxidised to $\text{Sn}^{4+}$ ions in this reaction.
How many moles of $\text{Mn}^{2+}$ ions are formed when a solution containing 9.5 g of $\text{SnCl}_2 \; (M_r:190)$ is added to an excess of acidified $\text{KMnO}_4$ solution?

Use of the Data Booklet is relevant to this question.
This question should be answered using bond enthalpy data. The equation for the complete combustion of methane is given below.
CH₄ + 2O₂ → CO₂ + 2H₂O
What is the enthalpy change of combustion of methane?

In which row of the table are all statements comparing the compounds of magnesium and barium correct?
[Table_1]

What happens when iodine solution is added to a solution of sodium bromide?

Element 85, astatine, is in Group VII. Concentrated sulfuric acid is added to sodium astatide. The mixture of products includes astatine, hydrogen astatide, hydrogen sulfide, and sodium sulfate.
Which product is formed by the oxidation of one of the constituents of sodium astatide?

Use of the Data Booklet is relevant to this question.
Magnesium nitrate, Mg(NO$_3$)$_2$, will decompose when heated to give a white solid and a mixture of gases. One of the gases released is an oxide of nitrogen, X.
7.4 g of anhydrous magnesium nitrate is heated until no further reaction takes place.
What mass of X is produced?

Y is a salt of one of the halogens chlorine, bromine, iodine, or astatine (element 85).
The reaction scheme shows a series of reactions using a solution of Y as the starting reagent.



What could Y be?

Sulfur trioxide is manufactured from sulfur dioxide and oxygen, using the Contact process.
Which condition affects the value of the equilibrium constant, $K_c$?

Which reagent, when mixed and heated with ammonium sulfate, liberates ammonia?

The following compounds are found in the seaweed Asparagopsis taxiformis.
Which compound could show both cis-trans isomerism and optical isomerism?

Lactic acid (2-hydroxypropanoic acid), $\text{CH}_3\text{CH(OH)CO}_2\text{H}$, is found in sour milk. Which reaction could occur with lactic acid?

Bromine reacts with ethene to form 1,2-dibromoethane.
What is the correct description of the organic intermediate in this reaction?

Chloroethane can be used to make sodium propanoate.
chloroethane \rightarrow Q \rightarrow \text{sodium propanoate}
The intermediate, Q, is hydrolysed with boiling aqueous sodium hydroxide, to give sodium propanoate.
Which reagent would produce the intermediate, Q, from chloroethane?

Aqueous sodium hydroxide reacts with 1-bromopropane to give propan-1-ol.
How should the first step in the mechanism be described?

Pentane, $C_5H_{12}$, is reacted with chlorine in the presence of ultraviolet light. A compound R is found in the products. R has molecular formula $C_5H_{10}Cl_2$. Each molecule of R contains one chiral carbon atom.
Which two atoms of the pentane chain could be bonded to chlorine atoms in this isomer?

Use of the Data Booklet is relevant to this question.
2.30 g of ethanol were mixed with an excess of aqueous acidified potassium dichromate(VI). The reaction mixture was then boiled under reflux for one hour. The desired organic product was then collected by distillation. The yield of product was 60.0%.
What mass of product was collected?

Burnt sugar has a characteristic smell caused partly by the following compound:

This compound contains two functional groups. Which reagent will react with only one of the functional groups?

The structural formula of a compound $X$ is shown below.
What is the name of compound $X$ and how does its boiling point compare with that of butanoic acid?

Synthetic resins, plasticisers and many other chemicals can be made by polymerisation of a variety of monomers including prop-2-en-1-ol, CH$_2$=CHCH$_2$OH.
Which structure represents the repeat unit in poly(prop-2-en-1-ol)?

Some vegetable oils contain ‘trans fats’ that are associated with undesirable increases in the amount of cholesterol in the blood.
In the diagrams below, R_1 and R_2 are different hydrocarbon chains.
Which diagram correctly illustrates an optically active ‘trans fat’?

Free-radicals play an important part in reactions involving the destruction of the ozone layer and the substitution of alkanes by chlorine. Some free-radicals contain two unpaired electrons. Such species are called diradicals.
Which species are diradicals?
1. O
2. Cl
3. CH₃

The Group II metals have higher melting points than the Group I metals.
Which factors could contribute towards the higher melting points?
1 There are smaller interatomic distances in the metallic lattices of the Group II metals.
2 More electrons are available from each Group II metal atom for bonding the atom into the metallic lattice.
3 Group II metals have a higher first ionisation energy than the corresponding Group I metal.

Valence shell electron pair repulsion theory should be used to answer this question.
Which species are trigonal planar?

Which statements about this graph are correct?
1 Elements B, J and R are in Group 0 of the Periodic Table.
2 Atoms of elements D and L contain two electrons in their outer shells.
3 Atoms of elements G and O contain a half-filled p subshell.
[Image_1: Graph showing the first ionisation energies of twenty successive elements in the Periodic Table, represented in a graph with the element letters given not as normal symbols for these elements.]

Solids \( W, X, Y \) and \( Z \) are compounds of two different Group II metals. Some of their applications are described below.

Compound \( W \) is used as a refractory lining material in kilns.

Compound \( X \) is used as a building material. It can also be heated in a kiln to form compound \( Y \). When \( Y \) is hydrated, it forms compound \( Z \) which is used agriculturally to treat soils.

Which statements about these compounds are correct?

1. More acid is neutralised by 1 g of \( W \) than by 1 g of \( X \).
2. The metallic element in \( W \) reacts with water more quickly than the metallic element in \( Y \).
3. Adding \( Z \) to a soil decreases the pH of the soil.

When a red-hot platinum wire is plunged into a test tube of hydrogen iodide, the gas is decomposed into its elements. If the experiment is repeated with hydrogen chloride, no change occurs.
Which factors contribute to this behaviour?
1. the strength of the hydrogen-halogen bond
2. the size of the halogen atom
3. the standard enthalpy of formation, $\Delta H_f^\circ$, of each of the products of decomposition

Which molecules would be present in the mixture produced by the photochemical chlorination of methane?

In which reactions is the organic compound oxidised by the given reagent?
1. $\text{CH}_3\text{CH}_2\text{CHO} + \text{Fehling's reagent}$
2. $\text{CH}_3\text{CH}_2\text{CH}_2\text{CHO} + \text{Tollens' reagent}$
3. $\text{CH}_3\text{CHO} + \text{2,4-dinitrophenylhydrazine reagent}$

A sun protection cream contains the following ester as its active ingredient.
Which substances are present in the products of its hydrolysis by aqueous sodium hydroxide?

Which reagents, when used in an excess, can be used to make sodium lactate, $CH_3CH(OH)CO_2Na$, from lactic acid, $CH_3CH(OH)CO_2H$?