Reacting Masses

Sodium hydroxide reacts with sulphuric acid as follows:

2 NaOH(aq) + H₂SO₄(aq) → Na₂SO₄(aq) + 2 H₂O(l)

Determine the mass of sodium sulphate, Na₂SO₄, produced when 20 g of NaOH reacts with excess H₂SO₄.

• 45 g

• 35.5 g

• 71 g

• 20 g

Calculate the mass of aluminium that can be formed from 1020 g of aluminium oxide.

2Al₂O₃ → 4Al+3O₂

• 27 g

• 270 g

• 1020 g

• 540 g

Calculate the mass of oxygen needed to react 10.0 g of calcium to form calcium oxide.

2Ca+O₂ →2CaO

• 8 g

• 2 g

• 4 g

• 16 g

What mass of propane could burn in 48.0 g of oxygen?

C₃H₈ +5O₂ →3CO₂ +4H₂O

• 66 g

• 13.2 g

• 26.4 g

• 33 g

What mass of ammonia can be made from 20.0 g of hydrogen?

3 H₂ + N₂ → 2 NH₃

• 113.3 g

• 170 g

• 226.6 g

• 85 g

What mass of sodium hydroxide is needed to neutralise 24.5 kg of sulphuric acid? H₂SO₄ + 2 NaOH → Na₂SO₄ + 2 H₂O

• 40 kg

• 15 kg

• 10 kg

• 20 kg

What mass of carbon dioxide is formed when 7.41 g of copper(II) carbonate decomposes on heating?

CuCO₃ → CuO + CO₂

• 5.28 g

• 4.18g

• 2.64 g

• 3.64 g

When nonane (C9H20) burns the equation is:

C₉H₂₀(g) + 14 O₂(g) → 9 CO₂(g) + 10 H₂O(l)

What mass of nonane will give 1000 g of CO₂?

• 323.2 g

• 2.909 kg

• 402 g

• 646.4 g

Iron is formed in the Blast Furnace by reduction of heamatite (Fe₂O₃) with carbon monoxide according to the equation,

Fe₂O₃ +3CO →2Fe+3CO₂

What mass of iron can be obtained by reduction of 8 tonnes (1 tonne = 1 × 10⁶ g) of

heamatite? Assume a plentiful supply of carbon monoxide.

• 2.8 x 10⁶ g

• 280 kg

• 5600 kg

• 56 tonnes

Zinc can be purified from its oxide by reacting it with Carbon

2 ZnO(s) + C(s) → 2 Zn(s) + CO₂(g)

When Gavin reacted 2.43 g of ZnO he obtained 1.40 g of Zinc. What is the % yield of this reaction?

• 72 %

• 62 %

• 75 %

• 81 %