0654.C3.3.05 — Calculate stoichiometric reacting masses, limiting reactants, volumes of gases at r.t.p., including conversion between cm3 and dm3: past paper questions
Real questions on 0654.c3.3.05 — calculate stoichiometric reacting masses, limiting reactants, volumes of gases at r.t.p., including conversion between cm3 and dm3
The newest 12 of 12 written questions. Open one to see it on the real paper.
- 0973/41 · May/June 2025 · Q6f[3]
Some coal burns to make 11 000 g of carbon dioxide gas. Calculate the volume occupied by 11 000 g of carbon dioxide gas. The volume of one mole of any gas is 24 dm 3 at room temperature and pressure (r.t.p.). [A r : C, 12; O, 16] volume of carbon dioxide gas = dm 3
See it on the paper → - 0973/41 · May/June 2025 · Q8c[3]
A mixture containing 5.6 g of ethene, C 2 H 4 , is allowed to react with 5.4 g of steam. Ethanol, C 2 H 5 OH, is made. C 2 H 4 + H 2 O C 2 H 5 OH Determine the limiting reactant in this reaction. Show your working. [A r : C, 12; H, 1; O, 16]
See it on the paper → - 0973/42 · May/June 2024 · Q5c[3]
Calculate the volume occupied by 1.1 g of carbon dioxide gas at room temperature and pressure. The volume of one mole of any gas is 24 dm 3 at room temperature and pressure (r.t.p.). [A r : C, 12; O, 16] volume of carbon dioxide gas = dm 3
See it on the paper → - 0973/41 · October/November 2023 · Q5d[4]
2.45 g of sulfuric acid reacts with 1.60 g of copper oxide. Copper sulfate, CuSO 4 , is made. H 2 SO 4 + CuO CuSO 4 + H 2 O Calculate the number of moles of sulfuric acid and the number of moles of copper oxide. Use your answers to determine the limiting reactant in this reaction. Show your working. [A r : H, 1; Cu, 64...
See it on the paper → - 0973/41 · October/November 2023 · Q8b(i)[3]
Iron reacts with oxygen to make hydrated iron oxide (rust). 4Fe + 3O 2 + 6H 2 O 4Fe(OH) 3 224 g of oxygen reacts with iron to make 1 kg of rust. Calculate the volume occupied by 224 g of oxygen gas. The molar gas volume at room temperature and pressure is 24 dm 3 . [A r : O, 16] volume of oxygen gas = dm 3
See it on the paper → - 0973/41 · May/June 2022 · Q5c(ii)[2]
Ammonia, NH 3 , reacts with nitric acid, HNO 3 . Ammonium nitrate, NH 4 NO 3 , is made. Look at the equation for the reaction. NH 3 + HNO 3 NH 4 NO 3 Calculate the mass of ammonium nitrate made from 51 kg of ammonia. Show your working. [A r : H, 1; N, 14; O, 16] mass = kg
See it on the paper → - 0973/41 · May/June 2021 · Q8c(ii)[3]
The total mass of bromine gas made in an electrolysis experiment is 20 g. Calculate the volume of bromine gas made. The volume of one mole of any gas is 24 dm 3 at room temperature and pressure (r.t.p.). Show your working. [A r : Br, 80] volume of bromine gas = dm 3
See it on the paper → - 0973/41 · October/November 2020 · Q5a(i)[1]
Use Fig. 5.2 to state the mass of carbon dioxide made after 2.5 minutes using cold acid.
See it on the paper → - 0973/41 · October/November 2020 · Q5a(ii)[1]
Warm acid reacts faster with calcium carbonate than cold acid. Explain why both reactions make 1.2 g of carbon dioxide gas.
See it on the paper → - 0973/41 · October/November 2020 · Q5a(iii)[3]
Calculate the volume occupied by 1.2 g of carbon dioxide gas at 25 °C. The molar gas volume at 25 °C is 24 dm 3 . [A r : C, 12; O, 16] volume = dm 3
See it on the paper → - 0973/42 · May/June 2020 · Q13c[3]
A mixture containing 3.9 g of ethene and 4.0 g of steam is allowed to react. Ethanol, C 2 H 6 O, is made. C 2 H 4 + H 2 O C 2 H 6 O Determine the limiting reactant in this reaction. Show your working and explain your answer. [A r : C, 12; H, 1; O, 16] limiting reactant explanation
See it on the paper → - 0973/42 · May/June 2019 · Q11d[4]
The overall equation for the Contact process is raw materials product 2S + 3O 2 + 2H 2 O 2H 2 SO 4 Complete steps 1 to 4 to calculate the mass of sulfuric acid made from 1000 g of sulfur. Show your working. [A r : H,1; O,16; S,32] Step 1 Calculate the number of moles in 1000 g of sulfur. number of moles = Step 2 Deduce...
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What examiners said
The correct answer of 6000 dm3 was frequently seen. The majority of candidates correctly calculated the Mr of CO2 as 44.
— Examiner report, May/June 2025, 0973/41 Q6(f) (Cambridge)
Many responses correctly calculated the moles of ethene and steam and clearly displayed the working. The majority of candidates then went on to identify the correct limiting reactant. Some candidates calculated the molecular mass and just compared these, deducing that steam was the limiting reactant as it had less mass.
— Examiner report, May/June 2025, 0973/41 Q8(c) (Cambridge)
Candidates found this question about calculating the number of moles of sulfuric acid and the number of moles of copper oxide to determine the limiting reactant in the reaction challenging. Many candidates only calculated the relative formula mass of sulphuric acid and copper oxide and then compared these answers giving copper oxide being the limiting reactant as it had a smaller value. Other cand...
— Examiner report, October/November 2023, 0973/41 Q5(d) (Cambridge)
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