CHEMISTRY PAPER 1 (NO. 9)

Stearic acid has a melting point of 69 °C.
A heated sample of pure stearic acid is cooled and the temperature is recorded every minute for
30 minutes. A graph of the results is shown.

Which process occurs between 8 and 12 minutes?

Which statements are correct?
1
The volume of a gas at constant pressure increases as the temperature increases.
2
When the pressure of a gas is increased the particles move closer together.
3
The pressure of a gas at constant volume decreases as the temperature increases.

Which substance would diffuse most quickly?

Which diagram shows the arrangement of particles inside a balloon containing a mixture of the
gases nitrogen and oxygen?

The ion Q2+ has three complete shells of electrons.
What is Q?

The symbols for two ions are shown.

Which statement is correct?

Two isotopes of chlorine are 35Cl and 37Cl.
Using these isotopes, how many different relative molecular masses are possible for the compound
with molecular formula C2H3Cl 3?

Ethane, C2H6, and ammonia, NH3, are covalent compounds.
The dot-and-cross diagrams of these compounds are shown.
Which statements are correct?
1
A molecule of ethane contains twice as many hydrogen atoms as a molecule of ammonia.
2
An unreacted nitrogen atom has five outer electrons.
3
In a molecule of ethane, the bond between the carbon atoms is formed by sharing two
electrons, one from each carbon atom.

What happens to an atom of a Group II element when it forms a compound with oxygen?

A compound contains 70% by mass of iron and 30% by mass of oxygen.
What is its empirical formula? [Ar: O, 16; Fe, 56]

The equation for the reaction between ethyne, C2H2, and oxygen is shown.
2C2H2(g) + xO2(g) → yCO2(g) + zH2O(g)
When the equation is balanced, what is x?

25.0 g of hydrated copper(II) sulfate crystals are heated to produce anhydrous copper(II) sulfate
and water.
CuSO4•5H2O(s) → CuSO4(s) + 5H2O(g)
What is the mass of anhydrous copper(II) sulfate formed?
[Mr: CuSO4, 160; H2O, 18]

The relative formula masses of four compounds are given.
A student has a 1.0 g sample of each compound.
Which sample contains the highest number of moles of oxygen atoms?

50.0 cm3 of 0.10 mol / dm3 silver nitrate, AgNO3, is added to 150.0 cm3 of 0.05 mol / dm3
sodium iodide, NaI, in a beaker.
After the reaction, solid silver iodide is present in the beaker.
What else is present?

When 0.1 mol of the hydrocarbon, C5H12, is completely combusted it produces carbon dioxide,
CO2, and water, H2O.
C5H12(l) + 8O2(g) → 5CO2(g) + 6H2O(g)
What is the volume of carbon dioxide produced when measured at room temperature and
pressure?

Carbon electrodes are used to electrolyse aqueous copper(II) sulfate.
Which observations are made?

Electrolysis is used to plate a metal coin with silver.
The coin is used as an electrode in a suitable electrolyte.
Which row is correct?

An endothermic reaction has an activation energy of x.
Which reaction pathway diagram is correct for this reaction?

The formation of liquid water from hydrogen and oxygen may occur in three stages.
1
2H2(g) + O2(g) → 4H(g) + 2O(g)
2
4H(g) + 2O(g) → 2H2O(g)
3
2H2O(g) → 2H2O(l)
Which stages are endothermic?

In four separate experiments, 1, 2, 3 and 4, nitric acid is added to an excess of marble pieces and
the volume of carbon dioxide gas formed is measured.
In all four experiments the same volume of nitric acid is used.
The concentration, or temperature, or both concentration and temperature of the nitric acid, are
changed.
The results of the experiments are shown on the graph.

Which statement is correct?

The equation shows the reaction for the manufacture of ammonia.
N2(g) + 3H2(g) ⇌ 2NH3(g)
Which change will decrease the activation energy of the reaction?

A reversible reaction is shown.
BiCl 3(aq) + H2O(l) ⇌ BiOCl (s) + 2HCl (aq)
Which changes increase the mass of the precipitate formed?
1
adding more water
2
adding aqueous sodium hydroxide
3
adding dilute hydrochloric acid

Sulfur trioxide is produced by the reversible reaction shown.
2SO2(g) + O2(g) ⇌ 2SO3(g) ∆H = −195 kJ / mol
Which change in conditions will produce a greater amount of SO3 at equilibrium?

Iron(II) ions react with chlorine.
2Fe2+(aq) + Cl 2(g) → 2Fe3+(aq) + 2Cl −(aq)
Which statement about this reaction is correct?

Which reactions involve oxidation and reduction?
1
chlorine gas reacting with aqueous potassium iodide
2
dilute sulfuric acid reacting with magnesium
3
dilute hydrochloric acid reacting with aqueous sodium hydroxide

Which statement about weak acids is correct?

A colourless aqueous solution of pH 13 is tested separately with methyl orange indicator and
thymolphthalein indicator.
Which row is correct?

Which pair of reagents is suitable for preparing a pure sample of copper(II) chloride crystals?

Element X forms an oxide of formula X2O5.
In which group of the Periodic Table is X likely to be found?

The diagram shows the structure of an alloy.

Which statement about alloys is correct?

Which compound has the lowest percentage by mass of nitrogen?

The diagrams show the structures of five hydrocarbons.

Which three hydrocarbons are isomers of each other?

The diagram shows a fractionating column used in the separation of petroleum.

Which row explains why fraction R is collected above fraction S?

Which compound is an alkane?

Which row correctly describes alkenes?

A carboxylic acid with molecular formula C4H8O2 reacts with an alcohol with molecular formula
C3H8O to form an ester.
What is the formula of the ester formed?

The repeat unit of a polymer is shown.

Which monomer would produce this polymer?

When heated, magnesium reacts with oxygen in the air to form magnesium oxide, a white powder.
A student investigates the change in mass that occurs during this reaction. The student is given a
balance and the three sets of apparatus shown.

Which sets of apparatus are suitable for this investigation?

A student uses paper chromatography to find an Rf value for Fe3+(aq). The result is shown.

To make the spot containing Fe3+(aq) more visible, the paper is sprayed with aqueous
sodium hydroxide so that a precipitate of iron(III) hydroxide forms.
Under the conditions of the experiment, the Rf value of Fe3+(aq) is given by …..1….. and the
colour of the precipitate is …..2….. .
Which row correctly completes gaps 1 and 2?

Tests on an aqueous solution of an unknown compound P are shown in the table.

Which ions are present in P?