plumiConservation of mass and moles: Edexcel GCSE Combined Science questions
Every Edexcel GCSE Combined Science exam question on Conservation of mass and moles (specification points 1.47–1.53), 2018–2025, with its mark scheme and examiner’s report.
Paper
All papers
Exam
All years
Calculations
Q3(c)
The whole paper ↗Q4(a)(iii)
The whole paper ↗Q5(b)(ii)
The whole paper ↗Q1(d)(i)
The whole paper ↗Q1(d)(ii)
The whole paper ↗Q3(c)(ii)
The whole paper ↗Q4(c)(iii)
The whole paper ↗Q4(d)
The whole paper ↗Q1(c)
The whole paper ↗Q3(c)
The whole paper ↗Q5(a)(ii)
The whole paper ↗Q5(c)
The whole paper ↗Q6(b)
The whole paper ↗Q6(c)
The whole paper ↗Q4(a)
The whole paper ↗Q2(b)
The whole paper ↗Q6(b)
The whole paper ↗Q4(c)
The whole paper ↗Q5(f)
The whole paper ↗Q6(b)
The whole paper ↗
All 58 questions on Conservation of mass and moles, as a list
- June 2025, Chemistry Paper 1 Higher, Q3(c) (2 marks): At high temperatures, nitrogen, N2, can react with oxygen, O2, to form nitrogen dioxide only. Write the balanced equation for this reaction. (2)
- June 2025, Chemistry Paper 1 Higher, Q4(a)(iii) (4 marks): The equation for the decomposition of malachite when it is heated is Cu2CO3(OH)2 → 2CuO + CO2 + H2O Calculate the maximum mass of copper oxide that can be forme
- June 2025, Chemistry Paper 1 Higher, Q5(b)(ii) (3 marks): Calculate the number of oxygen atoms in 7.20 g of MgSO4 . (relative formula mass: MgSO4 = 120 Avogadro constant = 6.02 × 1023) (3) number of oxygen atoms =
- June 2025, Chemistry Paper 1 Foundation, Q1(d)(i) (1 mark): Figure 2 shows the results the student records at the start of the investigation. mass of empty test tube 14.62 g mass of test tube + zinc carbonate 17.83 g Fig
- June 2025, Chemistry Paper 1 Foundation, Q1(d)(ii) (2 marks): The student then • heats the test tube containing the zinc carbonate for five minutes • places the hot test tube on a bench mat to cool • finds the mass of the
- June 2025, Chemistry Paper 1 Foundation, Q3(c)(ii) (2 marks): A student investigates the reaction between a metal and a dilute acid using the apparatus shown in Figure 7. Cotton wool is placed in the top of the apparatus a
- June 2025, Chemistry Paper 1 Foundation, Q4(c)(iii) (2 marks): In one reaction, 159.0 g of copper oxide was heated with excess carbon to produce 127.0 g of copper. Use this information to calculate the mass of copper formed
- June 2025, Chemistry Paper 1 Foundation, Q4(d) (3 marks): A solution of zinc sulfate was made by dissolving 23.8 g of the compound in water and was made up to a total volume of 250 cm3 with water. Calculate the concent
- June 2025, Chemistry Paper 2 Higher, Q1(c) (2 marks): The concentration of solution Q is 26.8 g dm–3. Calculate the mass of solid Q present in 25 cm3 of solution Q. mass of solid (g) concentration (g dm–3) = volume
- June 2025, Chemistry Paper 2 Higher, Q3(c) (2 marks): The relative atomic mass of caesium is 132.905. Calculate the average mass of one atom of caesium (Avogadro constant = 6.02 × 1023) (2) mass = g
- June 2025, Chemistry Paper 2 Higher, Q5(a)(ii) (2 marks): Calculate the mass, in kg, of five moles of Buckminsterfullerene, C60. (relative atomic mass: C = 12) (2) mass = kg
- June 2025, Chemistry Paper 2 Foundation, Q5(c) (2 marks): The concentration of solution Q is 26.8 g dm–3. Calculate the mass of solid Q present in 25 cm3 of solution Q. mass of solid (g) concentration (g dm–3) = volume
- June 2024, Chemistry Paper 1 Higher, Q6(b) (4 marks): The formula of lead ethanoate is Pb(CH3COO)2. Calculate the number of atoms that combine together to form 16.25 g of lead ethanoate. (relative atomic masses: H
- June 2024, Chemistry Paper 1 Higher, Q6(c) (3 marks): Iron is more reactive than copper. Iron will displace copper from copper nitrate solution. Two possible balanced equations for the reaction are Equation 1 Fe +
- June 2024, Chemistry Paper 1 Foundation, Q4(a) (2 marks): A 250 cm3 solution of copper sulfate contains 6.52 g of dissolved solid. Calculate the concentration of this copper sulfate solution in g dm–3. mass of solid (g
- June 2024, Chemistry Paper 2 Higher, Q2(b) (2 marks): Copper reacts with oxygen to form copper oxide. 2.100 g of copper will react completely with 0.529 g of oxygen. In an experiment, 4.200 g of copper is heated wi
- June 2024, Chemistry Paper 2 Foundation, Q6(b) (2 marks): Copper reacts with oxygen to form copper oxide. 2.100 g of copper will react completely with 0.529 g of oxygen. In an experiment, 4.200 g of copper is heated wi
- June 2023, Chemistry Paper 1 Higher, Q4(c) (3 marks): In another experiment, 74 mg of copper is formed. Calculate the number of copper atoms in 74 mg of copper. (relative atomic mass Cu = 63.5; Avogadro constant =
- June 2023, Chemistry Paper 1 Higher, Q5(f) (1 mark): In another experiment, a copper sulfate solution with a concentration of 39.875 g dm–3 is used. Calculate the mass of copper sulfate dissolved in 0.300 dm3 of t
- June 2022, Chemistry Paper 1 Higher, Q6(b) (4 marks): The formula of aluminium sulfate is Al2(SO4)3. Calculate the total number of atoms that combine to form 5.13 g of aluminium sulfate. (relative atomic masses: O
- June 2022, Chemistry Paper 1 Higher, Q6(c) (3 marks): Iron is more reactive than lead. Iron reacts with lead nitrate solution to form solid lead. Two possible balanced equations for the reaction are Equation 1 Fe +
- June 2022, Chemistry Paper 1 Foundation, Q4(a) (2 marks): 3.14 g of solid copper sulfate was dissolved in water and made up to 250 cm3 of solution. mass of solid (g) concentration (g dm−3) = 3 volume of solution (dm )
- June 2022, Chemistry Paper 1 Foundation, Q4(b)(ii) (1 mark): Complete the balanced equation for the reaction by adding a number in front of NaOH. (1) NaOH + CuSO4 → Cu(OH)2 + Na2SO4
- June 2022, Chemistry Paper 2 Higher, Q2(c) (2 marks): When calcium carbonate is heated it decomposes. CaCO3(s) → CaO(s) + CO2(g) When 5.000 g of calcium carbonate is heated, the mass of solid remaining is 2.800 g.
- June 2022, Chemistry Paper 2 Higher, Q2(e) (2 marks): Oxygen gas has the formula O2. Calculate the number of oxygen atoms in 3.50 mol of oxygen gas. (Avogadro constant = 6.02 × 1023) (2) number of oxygen atoms =
- June 2022, Chemistry Paper 2 Higher, Q5(b) (2 marks): Magnesium reacts with oxygen from the air to form magnesium oxide. A student carries out an investigation to determine the mass of magnesium oxide formed when a
- June 2022, Chemistry Paper 2 Foundation, Q6(c) (2 marks): When calcium carbonate is heated it decomposes. CaCO3(s) → CaO(s) + CO2(g) When 5.000 g of calcium carbonate is heated, the mass of solid remaining is 2.800 g.
- November 2021, Chemistry Paper 1 Higher, Q4(d) (4 marks): Hydrated copper sulfate has the formula CuSO4.5H2O. The formula tells us that each mole of copper sulfate contains 5 moles of water. A sample of CuSO4.5H2O was
- November 2021, Chemistry Paper 1 Higher, Q5(d)(i) (2 marks): Calculate the number of moles in 45 000 grams of titanium chloride. (relative atomic masses: Cl = 35.5, Ti = 48.0) (2) number of moles titanium chloride =
- November 2021, Chemistry Paper 1 Higher, Q5(d)(ii) (1 mark): Show that the 500 moles of magnesium added is an excess. (1)
- November 2021, Chemistry Paper 1 Foundation, Q1(b)(iii) (2 marks): Calculate the mass of calcium ions in 250 cm3 of this drinking water. (2) mass = mg
- November 2021, Chemistry Paper 2 Higher, Q1(a) (2 marks): The concentration of a solution can be calculated using the equation mass of solid concentration of solution = volume of solution A student dissolved 9.25g of a
- November 2021, Chemistry Paper 2 Foundation, Q5(a) (2 marks): The concentration of a solution can be calculated using the equation mass of solid concentration of solution = volume of solution A student dissolved 9.25g of a
- November 2020, Chemistry Paper 1 Higher, Q1(b) (3 marks): The sodium sulfate solution was made by dissolving 28.4 g of sodium sulfate in water to make 250 cm3 of solution. Calculate the concentration of this solution i
- November 2020, Chemistry Paper 1 Foundation, Q5(b) (3 marks): The sodium sulfate solution was made by dissolving 28.4 g of sodium sulfate in water to make 250 cm3 of solution. Calculate the concentration of this solution i
- November 2020, Chemistry Paper 2 Higher, Q3(a)(iii) (1 mark): You are provided with some dilute hydrochloric acid which has a concentration of 50 g dm–3. For this experiment, dilute hydrochloric acid with a concentration o
- November 2020, Chemistry Paper 2 Higher, Q5(a)(iii) (4 marks): 8.5 g of rubidium are reacted completely with water. The reaction makes a solution of rubidium hydroxide. The volume of this solution is 2.5 dm3. Calculate the
- November 2020, Chemistry Paper 2 Higher, Q5(b) (3 marks): An example of an endothermic reaction is the reaction between rubidium hydroxide and ammonium carbonate, (NH4)2CO3. This reaction forms rubidium carbonate, Rb2C
- November 2020, Chemistry Paper 2 Foundation, Q2(a)(ii) (1 mark): The student recorded the total mass of the reactants and the total mass of the products. The results are shown in Figure 2. reactants products total mass in g 2
- November 2020, Chemistry Paper 2 Foundation, Q4(d)(ii) (2 marks): Dodecane is a large hydrocarbon molecule. When one molecule of dodecane is cracked the products are one molecule of octane and one molecule of butene. dodecane
- June 2019, Chemistry Paper 1 Higher, Q4(c) (2 marks): Calculate the number of atoms combined in one mole of copper iodide, CuI2. (Avogadro constant = 6.02 × 1023) (2) number of atoms =
- June 2019, Chemistry Paper 1 Higher, Q5(c) (3 marks): The copper sulfate solution used has a concentration of 15.95 g dm−3. Calculate the number of moles of copper sulfate, CuSO4, in 50.00 cm3 of this solution. (re
- June 2019, Chemistry Paper 1 Higher, Q5(d) (2 marks): In another experiment, 0.043 mol of copper sulfate, CuSO4, is used. Calculate, to one decimal place, the minimum mass of zinc that must be added to react with a
- June 2019, Chemistry Paper 2 Higher, Q2(b) (3 marks): Magnesium burns in excess oxygen to form magnesium oxide. The balanced equation for this reaction is 2Mg + O2 → 2MgO Starting with 1.35g of magnesium, calculate
- June 2019, Chemistry Paper 2 Higher, Q3(c) (3 marks): Calculate the number of molecules in 0.11 g of carbon dioxide. Give your answer to two significant figures. (relative formula mass : CO2 = 44 Avogadro constant
- June 2019, Chemistry Paper 2 Foundation, Q3(e) (3 marks): The concentration of a calcium chloride solution is 12 g dm–3. Calculate the volume of this solution, in cm3, that contains 9.0 g of calcium chloride. You must
- June 2019, Chemistry Paper 2 Foundation, Q4(b) (2 marks): Explain why there is a loss in mass of the flask and contents. (2)
- June 2019, Chemistry Paper 2 Foundation, Q6(b) (3 marks): Magnesium burns in excess oxygen to form magnesium oxide. The balanced equation for this reaction is 2Mg + O2 → 2MgO Starting with 1.35g of magnesium, calculate
- June 2018, Chemistry Paper 1 Higher, Q1(b) (2 marks): A nickel sulfate solution is made by dissolving 23.5 g of nickel sulfate to make 250 cm3 of solution. Calculate the concentration of the solution in g dm−3. (2)
- June 2018, Chemistry Paper 1 Higher, Q2(a)(ii) (3 marks): The formula of the iron oxide is Fe2O3. Calculate the maximum mass of iron that can be obtained from 240 tonnes of iron oxide, Fe2O3. (relative atomic masses: O
- June 2018, Chemistry Paper 1 Higher, Q6(b) (2 marks): When iron reacts with copper sulfate solution, solid copper is formed. Two possible equations for this reaction are A CuSO4 + Fe o Cu + FeSO4 B 3CuSO4 + 2Fe o 3
- June 2018, Chemistry Paper 1 Higher, Q6(e) (3 marks): Calculate the mass, in g, of a hydrogen atom, using the data below. (relative atomic mass: H = 1.00; Avogadro constant = 6.02 × 1023) (3) mass of hydrogen atom
- June 2018, Chemistry Paper 1 Foundation, Q2(c)(i) (2 marks): Balance the equation for this reaction by putting numbers in the spaces provided. (2) C4H8 + 6O2 o CO2 + H2O
- June 2018, Chemistry Paper 1 Foundation, Q3(d)(i) (1 mark): A beaker of barium chloride solution and a beaker of dilute sulfuric acid were placed on a balance, as shown in Figure 3. dilute sulfuric acid barium chloride s
- June 2018, Chemistry Paper 1 Foundation, Q5(d) (2 marks): A nickel sulfate solution is made by dissolving 23.5 g of nickel sulfate to make 250 cm3 of solution. Calculate the concentration of the solution in g dm–3. (2)
- June 2018, Chemistry Paper 1 Foundation, Q6(a)(ii) (3 marks): The formula of the iron oxide is Fe2O3. Calculate the maximum mass of iron that can be obtained from 240 tonnes of iron oxide, Fe2O3. (relative atomic masses: O
- June 2018, Chemistry Paper 2 Higher, Q6(b)(i) (1 mark): In another experiment, 0.1 moles of hydrochloric acid, HCl, were reacted with 0.1 g of magnesium ribbon. Calculate the number of moles of magnesium, Mg, in the
- June 2018, Chemistry Paper 2 Higher, Q6(b)(ii) (1 mark): In a further experiment, 0.5 mol of hydrochloric acid, HCl, were mixed with 0.5 mol of magnesium, Mg. Use the equation to show that, in this experiment, the mag
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