Quiz 21.07.21

Which statement about atoms and molecules is correct?

• All molecules are gases at room temperature and pressure.

• An atom is the smallest part of an element.

• Atoms of the same element all have the same mass.

• Molecules always contain atoms of more than one element.

Which compound is formed when one metal atom transfers two electrons to one non-metal atom?

• calcium chloride

• calcium oxide

• sodium chloride

• sodium oxide

What is the volume of 0.35 mol of hydrogen gas at room temperature and pressure?

• 2.1 dm3

• 4.2 dm3

• 8.4 dm3

• 16.8 dm3

The diagram shows the electrolysis of lead(II) bromide using inert electrodes. electrode X electrode Y electrolyte grey solid coloured fumes Which statement about this experiment is correct?

• Electrode X is positively charged.

• The coloured fumes are produced at the negative electrode.

• The electrolyte is lead(II) bromide.

• The grey solid is lead(II) bromide.

An acid reacts with solid lumps of calcium carbonate to produce a salt, water and carbon dioxide. Which changes lead to a greater frequency of successful collisions between reacting particles?

1 Increase the temperature of the acid.

2 Use powdered lumps of calcium carbonate.

3 Use a different acid with a higher pH.

• 1 and 2 only

• 1 and 3 only

• 2 and 3 only

• 1, 2 and 3

The ionic equation for the formation of chromium(III) ions is shown.

Cr → Cr³⁺ + 3e^–

Which statement about chromium atoms is correct?

• They are oxidised by gaining electrons.

• They are oxidised by losing electrons.

• They are reduced by gaining electrons.

• They are reduced by losing electrons.

X is an oxide. When solid X is added to dilute hydrochloric acid, the pH of the solution increases. When solid X is added to aqueous sodium hydroxide, the pH of the solution decreases. Which type of oxide is X?

• acidic

• amphoteric

• basic

• neutral

Copper sulfate is made by adding an excess of copper carbonate to dilute sulfuric acid and stirring. The excess solid is removed. Most of the water is then removed. The solution is left for solid copper sulfate to form. In which order is apparatus used?

• Bunsen burner, tripod and flask → filter funnel → crystallising dish

• Bunsen burner, tripod and flask → crystallising dish → filter funnel

• filter funnel → crystallising dish → Bunsen burner, tripod and flask

• filter funnel → Bunsen burner, tripod and flask → crystallising dish

Which statement is not a reason why aluminium is used in aircraft manufacture?

• It forms low density alloys.

• It is malleable.

• It is more reactive than iron.

• It is resistant to corrosion.

What happens to a tellurium atom when it forms a tellurium ion, Te^2–?

• It gains two electrons.

• It gains two protons.

• It loses two electrons.

• It loses two protons