iGCSE stoichiometry quiz

The equation shows the reaction between magnesium and sulfuric acid.

[Ar: H, 1; O, 16; Mg, 24; S, 32]

Mg + H₂SO₄ → MgSO₄ + H₂

In this reaction, which mass of magnesium sulfate is formed when 6g of magnesium react with excess sulfuric acid?

• 8

• 24

• 30

• 60

Two atoms of magnesium, Mg, react with one molecule of oxygen, O₂. What is the formula of the product?

• MgO

• MgO₂

• Mg₂O

• Mg₂O₂

What is the relative formula mass, Mr, of CaCO₃?

Ar Ca: 40, C: 12, O:16

• 50

• 68

• 100

• 204

• A

• B

• C

• D

The complete combustion of methane produces CO2 and steam.

CH₄ + 2O₂ -> 2H₂O (g) + CO₂ (g)

Tick ALL boxes that are correct

• the empirical formula of methane is CH₄

• The number of atoms in 1 mole of methane is 4 x 6 x 10²³

• 1 mole of methane produce 72 dm³ of gaseous products at rtp

• 1 mole of methane occupies a volume of 12 dm³ at rtp

Calcium carbide and water react to produce ethyne and calcium hydroxide. What is the volume of C₂H₂ in dm³ produced when 45g of water reacts completely? (Ar: H:1, O:16)

• 72

• 30

• 24

• 6

What is volume of CO2 in dm³ produced when 21g of magnesium carbonate MgCO₃ reacts completely with excess acid?

• 4

• 8

• 6

• 2

Calcium carbonate undergoes thermal decomposition to form calcium oxide and carbon dioxide. What mass of CaO, in grams, is formed when 60g of CaCO₃ decomposes?

• 28

• 18.5

• 60

• 33.6

How many kg of aluminium oxides are formed from 5.4 kg of aluminium reacting with excess oxygen? (Ar: Al 27, O:16)

• 5.4

• 88

• 10.2

• 33.6

Magnesium nitride and water react to produce a precipitate of magnesium hydroxide and ammonia gas.

How much magnesium nitride is needed to produce 87g of the precipitate?

Mg: 24

N: 14

O: 16

H: 1

• 24 g

• 50 g

• 30 g

• 12 g