REVISION

The particles of a substance gain energy and change from a regular ordered structure to a disordered structure with large distances between the particles.

Which change of state is described?

• boiling

• evaporation

• melting

• sublimation

Which statements about isotopes of the same element are correct?

1 They are atoms which have the same chemical properties because they have the same number of electrons in their outer shell.

2 They are atoms which have the same chemical properties because they have the same number of electrons in their outer shell.

3 They are atoms which have the same number of electrons and protons but different numbers of neutrons.

• 1 and 2

• 1 and 3

• 2 only

• 3 only

Which statement describes the attractive forces between molecules (intermolecular forces)?

• They are strong covalent bonds which hold molecules together

• They are strong ionic bonds which hold molecules together.

• They are weak forces formed between covalently-bonded molecules

• They are weak forces which hold ions together in a lattice.

Metals consist of a lattice of positive ions in a ‘sea of electrons’. Why is aluminium malleable?

• Its ions are attracted to the ‘sea of electrons’.

• Its ions are tightly packed together.

• Its ions repel each other.

• Its layers of ions can slide over each other.

Silver chloride is insoluble in water and is prepared by precipitation. Which two substances can be used to make silver chloride?

• barium chloride and silver nitrate

• hydrochloric acid and silver

• hydrochloric acid and silver bromide

• sodium chloride and silver iodide

Rubidium is a Group I metal.

Which statement about rubidium is not correct?

• It has a higher melting point than lithium

• It has one electron in its outer shell.

• It reacts vigorously with water.

• It reacts with chlorine to form rubidium chloride, RbCl .

Which property is not considered a typical metallic property?

• good conductor of heat

• low melting point

• malleable (can be hammered into shape)

• strong

During a reaction, the following changes take place.

1) Temperature rises

2) A gas is given off

Which apparatus is required to measure the rate of this reaction?

• balance and burette

• balance and gas syringe

• gas syringe and burette

• gas syringe and stopclock

Which statement about bonding is not correct?

• Carbon can form four single covalent bonds.

• Chlorine atoms react to gain a noble gas electronic structure.

• Covalent bonding involves losing and gaining electrons.

• Hydrogen molecules have the formula H₂.

Which equation for the reaction between sodium carbonate and dilute hydrochloric acid is correct?

• Na₂CO_3(s) + HCl(aq) → NaCl(aq) + CO₂(g) + H₂O(I)

• Na₂CO₃(s) + HCl(aq) → Na₂Cl(aq) + CO₂(g) + H₂O(I)

• Na₂CO₃(s) + 2HCl(aq) → NaCl(aq) + CO₂(g) + H₂O(I)

• Na₂CO₃(s) + 2HCl(aq) → 2NaCl(aq) + CO_2(g) + H₂O(I)