Chemistry Revision V.1

Pure water boils at 100 °C.

What happens to the water particles when water boils?

• They gain energy and move further apart.

• They gain energy and stay close together.

• They lose energy and move further apart.

• They lose energy and stay close together.

Which method should be used to separate a mixture of two liquids?

• crystallisation

• electrolysis

• filtration

• fractional distillation

Lead(II) iodide is insoluble in water.

Lead(II) iodide is made by adding aqueous lead(II) nitrate to aqueous potassium iodide.

Which pieces of apparatus are needed to obtain solid lead(II) iodide from 20 cm^3 of aqueous

lead(II) nitrate?

• 1, 2, and 4

• 1, 3, and 5

• 1, 4, and 5

• 2, 4, and 5

The chromatogram of substance S is shown.

Some distances, W, X, Y and Z, are labelled on the diagram. How is the Rf value of substance S calculated?

• X/Y

• W/Z

• Y/X

• Y/W

Which row describes isotopes of the same element?

• number of protons: different | number of neutrons: different

• number of protons: different | number of neutrons: same

• number of protons: same | number of neutrons: different

• number of protons: same | number of neutrons: same

Which row describes the structure of the positive ion in sodium chloride?

• protons: 11 | electrons: 11 | neutrons: 12

• protons: 11 | electrons: 10 | neutrons: 12

• protons: 17 | electrons: 17 | neutrons: 18

• protons: 17 | electrons: 18 | neutrons: 18

Which statement about copper, diamond and silicon(IV) oxide is correct?

• Copper and silicon(IV) oxide have similar electrical conductivity.

• In diamond the carbon atoms are covalently bonded as flat sheets.

• In silicon(IV) oxide the silicon and oxygen atoms are covalently bonded as flat sheets.

• The structure of copper includes a lattice of positive ions.

An oxide of nitrogen has the following composition by mass: N, 30.4%; O, 69.6%.

It has a relative molecular mass of 92.

What is the molecular formula of the oxide of nitrogen?

• NO

• NO2

• NO4

• N2O4

Calcium carbonate reacts with dilute hydrochloric acid according to the equation shown.

CaCO3 + 2HCl → CaCl2 + CO2 + H2O

10 g of calcium carbonate is reacted with 100 cm^3 of 1 mol / dm3 hydrochloric acid.

The following statements are made.

1 1.2 dm3 of carbon dioxide is formed.

2 5.6 g of calcium chloride is formed.

3 4.8 g of carbon dioxide is formed.

4 No calcium carbonate is left when the reaction is completed.

Which statements about the reaction are correct?

• 1 and 2

• 1 and 4

• 2 and 3

• 3 and 4

10 g of ammonium nitrate is added to water at 25 °C and the mixture stirred.

The ammonium nitrate dissolves and, after one minute, the temperature of the solution is 10 °C.

Which word describes this change?

• endothermic

• exothermic

• neutralisation

• reduction