Introducing chemical reactions: OCR GCSE Chemistry A questions

Every OCR GCSE Chemistry A exam question on C3.1 Introducing chemical reactions, 2018–2025, with its mark scheme and examiner’s report.

All 127 questions on Introducing chemical reactions, as a list

June 2025, Paper 1 Foundation, Q9 (1 mark): Copper reacts with oxygen to make copper oxide. Which mass of oxygen reacts with 127 kg of copper to make 159 kg of copper oxide? copper + oxygen copper oxide 1
June 2025, Paper 1 Foundation, Q10 (1 mark): Methane, CH4, burns in oxygen, O2. Carbon dioxide, CO2, and water vapour, H2O, are made. CH4(g) + 2O2(…) CO2(g) + 2H2O(…) What are the missing state symbols in
June 2025, Paper 1 Foundation, Q17(c) (2 marks): The formula of citric acid is C6H8O7. Calculate the relative formula mass of citric acid. Relative atomic mass (Ar): C = 12.0 H = 1.0 O = 16.0 Relative formula
June 2025, Paper 2 Foundation, Q9 (1 mark): A solution of barium ions reacts with a solution of sulfate ions to form a white precipitate. Ba2+( ) + SO4 2–( ) BaSO4( ) What is the state symbol for each spe
June 2025, Paper 3 Higher, Q4 (1 mark): The diagram shows calcium carbonate, CaCO3, reacting with an acid. The equation for the reaction is: CaCO3(s) + 2HCl (aq) CaCl2(aq) + H2O(l) + CO2(g) What happe
June 2025, Paper 3 Higher, Q6 (1 mark): What is the relative formula mass of butanoic acid, C3H7COOH? Relative atomic mass (Ar): C = 12.0 H = 1.0 O = 16.0 A 29.0 B 44.0 C 88.0 D 120.0 Your answer [1]
June 2025, Paper 3 Higher, Q8 (1 mark): Propene has the molecular formula C3H6. What is the empirical formula? A CH2 B CH3 C CH2CHCH3 D C3H6 Your answer [1]
June 2025, Paper 3 Higher, Q22(e) (4 marks): Calcium nitrate, Ca(NO3)2, can also be made in the reaction between calcium and nitric acid. Ca + 2HNO3 Ca(NO3)2 + H2 60 g of calcium reacts with excess nitric
June 2025, Paper 3 Higher, Q23(a) (3 marks): The equation shows the displacement reaction between aluminium and chromium oxide. 2Al (s) + Cr2O3(s) Al 2O3(s) + 2Cr(s) Calculate the mass of chromium oxide ne
June 2025, Paper 3 Higher, Q23(b) (2 marks): Calculate the mass of one atom of chromium. Relative atomic mass (Ar): Cr = 52.0 Avogadro constant = 6.02 × 1023 Mass of one atom of chromium = g [2]
June 2025, Paper 4 Higher, Q22(c)(ii) (3 marks): The sum of the relative formula masses (Mr) of the reactants is 149.9. Identify element X. Use the Periodic Table. Relative atomic mass (Ar): H = 1.0 O = 16.0 X
June 2024, Paper 1 Foundation, Q2 (1 mark): Which of these changes is a chemical change? A Ice melting B Shaping hot metal with a hammer C Water condensing D Wood burning Your answer [1]
June 2024, Paper 1 Foundation, Q10 (1 mark): What is the balanced symbol equation for the reaction of methane with oxygen? A CH4 + O2 CO2 + H2O B CH4 + O2 CO2 + 2H2O C CH4 + 2O2 CO2 + H2O D CH4 + 2O2 CO2 +
June 2024, Paper 1 Foundation, Q11 (1 mark): 11.0 g of aluminium reacts with 43.4 g of chlorine to make 54.4 g of aluminium chloride. 2Al + 3Cl 2 2Al Cl 3 How much aluminium is required to make 217.6 g of
June 2024, Paper 1 Foundation, Q18(d)(ii) (1 mark): The molecular formula of the monomer used to make PET is C10H10O5. State the empirical formula of the monomer used to make PET. [1]
June 2024, Paper 1 Foundation, Q19(a)(ii) (1 mark): Sulfuric acid has the state symbol (aq). What does (aq) mean? [1]
June 2024, Paper 1 Foundation, Q23(d) (3 marks): Calculate the relative formula mass of a (C2H5)2O molecule. Relative atomic mass (Ar): C = 12.0 H = 1.0 O = 16.0 Relative formula mass = [3]
June 2024, Paper 2 Foundation, Q19(e) (4 marks): In another neutralisation reaction dilute sulfuric acid, H2SO4, reacts with potassium hydroxide solution, KOH. H2SO4 + 2KOH K2SO4 + 2H2O Calculate the mass of p
June 2024, Paper 3 Higher, Q9 (1 mark): What is the mass of one atom of beryllium, Be? Relative atomic mass (Ar): Be = 9.0. The Avogadro constant is 6.02 × 1023. 6.64 × 10–24 g A 1.50 × 10–23 g B 2.41
June 2024, Paper 3 Higher, Q13 (1 mark): Copper nitrate decomposes into copper oxide, nitrogen dioxide and oxygen. 2Cu(NO3)2 2CuO + 4NO2 + O2 How many moles of products are formed if 18 mol of copper n
June 2024, Paper 3 Higher, Q17(d) (3 marks): Calculate the relative formula mass of a (C2H5)2O molecule. Relative atomic mass (Ar): C = 12.0 H = 1.0 O = 16.0 Relative formula mass = [3]
June 2024, Paper 4 Higher, Q18(c)(ii) (3 marks): Calculate the mass of copper that can be made from 15 tonnes of copper oxide. 2CuO + C 2Cu + CO2 Give your answer to 2 significant figures. Relative atomic mass
June 2023, Paper 1 Foundation, Q5 (1 mark): What is the relative formula mass of iron chloride, FeCl 3? Relative atomic mass (Ar): Cl = 35.5 Fe = 55.8. A 91.3 B 126.8 C 162.3 D 202.9 Your answer [1]
June 2023, Paper 1 Foundation, Q7 (1 mark): Why can the mass of a reaction in an open conical flask decrease? A One of the products is a gas. B One of the products is a solid. C One of the reactants is a
June 2023, Paper 1 Foundation, Q10 (1 mark): 63.5 g of copper reacts to make 134.5 g of copper chloride, CuCl 2. Cu + Cl 2 CuCl 2 How much copper chloride will be made from 0.635 g of copper? A 0.01345 g B
June 2023, Paper 1 Foundation, Q15 (1 mark): Hydrochloric acid, HCl, reacts with magnesium, Mg. Magnesium chloride and hydrogen are made. What is the balanced symbol equation for this reaction? A 2HCl + Mg
June 2023, Paper 1 Foundation, Q18(c)(i) (1 mark): What is the empirical formula of octane? [1]
June 2023, Paper 1 Foundation, Q18(c)(ii) (3 marks): Calculate the relative formula mass of octane. Relative atomic mass (Ar): C = 12.0 H = 1.0. Relative formula mass = [3]
June 2023, Paper 2 Foundation, Q13 (1 mark): Calcium carbonate, CaCO3, thermally decomposes to make calcium oxide, CaO, and carbon dioxide. CaCO3 CaO + CO2 5.0 g of calcium carbonate makes 2.8 g of calcium
June 2023, Paper 2 Foundation, Q16(e) (3 marks): In another experiment, the teacher reacts 0.1 g of zinc with excess hydrochloric acid. Zn + 2HCl ZnCl 2 + H2 Calculate the mass of hydrogen gas made. Relative a
June 2023, Paper 3 Higher, Q7 (1 mark): How many moles are in 30 g of nitrogen, N2? Relative atomic mass (Ar): N = 14.0 A 0.47 mol B 0.93 mol C 1.07 mol D 2.14 mol [1] Your answer
June 2023, Paper 3 Higher, Q12 (1 mark): The empirical formula of a compound is CH2O. The relative formula mass of the compound is 180.0. What is the molecular formula of the compound? Relative atomic
June 2023, Paper 3 Higher, Q14 (1 mark): What is the correct balanced equation for the combustion of hexane, C6H14? A C6H14 + 13O2 6CO2 + 7H2O B C6H14 + 6O2 6CO2 + 7H2O C 2C6H14 + 19O2 12CO2 + 14H2O D
June 2023, Paper 3 Higher, Q20(c)(ii) (2 marks): Some of this sulfur in seawater is in the form of magnesium sulfate, MgSO4. What is the relative formula mass of a sample of magnesium sulfate, MgSO4, where all
June 2023, Paper 3 Higher, Q22(a)(i) (3 marks): Calculate the mass of oxygen made when 0.45 moles of magnesium nitrate decomposes. Relative atomic mass (Ar): O = 16.0. Mass of oxygen = g [3]
June 2023, Paper 3 Higher, Q22(a)(ii) (3 marks): Calculate how many molecules of nitrogen dioxide, NO2, are produced from 0.45 moles of magnesium nitrate. The Avogadro constant is 6.02 × 1023. Give your answer
June 2023, Paper 3 Higher, Q22(c)(ii) (2 marks): A solution containing magnesium ions reacts with a solution containing hydroxide ions. Solid magnesium hydroxide is made. Write the balanced ionic equation for
June 2023, Paper 4 Higher, Q18(a) (2 marks): Write the balanced symbol equation for the reaction between hydrochloric acid, HCl , and magnesium. [2]
June 2022, Paper 1 Foundation, Q1 (1 mark): Which state symbol is used for liquids? A (aq) B (g) C (l) D (s) Your answer [1]
June 2022, Paper 1 Foundation, Q11 (1 mark): What is the relative formula mass of potassium chloride, KCl ? Relative atomic mass (Ar): Cl = 35.5 K = 39.1 A 36.0 B 67.4 C 74.6 D 79.0 Your answer [1]
June 2022, Paper 1 Foundation, Q17(b)(ii) (1 mark): The diagram shows the apparatus the student uses. Conical flask Dilute hydrochloric acid Magnesium carbonate Balance 154.2 g Stopwatch How can the student tell
June 2022, Paper 1 Foundation, Q17(b)(iii) (2 marks): The student records the mass on the balance every 2 minutes for 12 minutes. The student’s results are shown in the table. Time (minutes) Mass (g) 0 154.2 2 150.
June 2022, Paper 1 Foundation, Q21(d) (3 marks): Ethene reacts with bromine to make a product. The relative formula mass of the product is 187.8. There are 2 carbon atoms and 4 hydrogen atoms in the product. C
June 2022, Paper 1 Foundation, Q22(a)(ii) (1 mark): The student finds out that the sample is impure. The sample contains hexane, C6H14, and cyclohexane, C6H12. What is the empirical formula of hexane? [1]
June 2022, Paper 1 Foundation, Q22(b)(ii) (1 mark): Hexane reacts with oxygen in a combustion reaction. Complete the balanced symbol equation for this reaction. 2 C6H14 + O2 CO2 + H2O [1]
June 2022, Paper 2 Foundation, Q20(d) (3 marks): A catalytic converter on a car removes nitrogen monoxide and carbon monoxide from exhaust gases. Nitrogen gas and carbon dioxide gas are made. This is the equat
June 2022, Paper 2 Foundation, Q22(a) (2 marks): Write the balanced symbol equation for this reaction. [2]
June 2022, Paper 3 Higher, Q13 (1 mark): A sample of propanoic acid, C3H6O2, is made using an isotope of hydrogen, called deuterium. The relative atomic mass of deuterium is 2.0. What is the relative m
June 2022, Paper 3 Higher, Q16(d) (3 marks): Ethene reacts with bromine to make a product. The relative formula mass of the product is 187.8. There are 2 carbon atoms and 4 hydrogen atoms in the product. C
June 2022, Paper 3 Higher, Q17(a)(ii) (1 mark): The student finds out that the sample is impure. The sample contains hexane, C6H14, and cyclohexane, C6H12. What is the empirical formula of hexane? [1]
June 2022, Paper 3 Higher, Q17(b)(ii) (1 mark): Hexane reacts with oxygen in a combustion reaction. Complete the balanced symbol equation for this reaction. 2 C6H14 + O2 CO2 + H2O [1]
June 2022, Paper 3 Higher, Q21(a)(i) (2 marks): A scientist starts the reaction with 2.0 mol of phosphorus, P4. Calculate the mass of 2.0 mol of phosphorus. Mass of phosphorus = g [2]
June 2022, Paper 3 Higher, Q21(a)(ii) (3 marks): Calculate the maximum mass of phosphorus trichloride, PCl 3, that could be made from 2.0 mol of phosphorus, P4. Maximum mass of phosphorus trichloride = g [3]
June 2022, Paper 3 Higher, Q22(a) (3 marks): Calculate the mass of one atom of zinc. The Avogadro constant is 6.02 × 10–23. Give your answer to 3 significant figures. Mass of one atom of zinc = g [3]
June 2022, Paper 4 Higher, Q16(a) (2 marks): Write the balanced symbol equation for this reaction. [2]
November 2021, Paper 1 Foundation, Q4 (1 mark): Which statement describes a chemical change? A Acid being neutralised B Ice melting C Salt dissolving in water D Water boiling Your answer [1]
November 2021, Paper 1 Foundation, Q15 (1 mark): Butane is a hydrocarbon. The displayed formula of butane is shown. H H H H H C C C C H H H H H What is the empirical formula of butane? A CH B CH2 C C2H5 D C4H1
November 2021, Paper 1 Foundation, Q16(b) (1 mark): Zinc reacts with nitric acid. Look at the balanced symbol equation for the reaction. Zn(s) + 2HNO3(aq) Zn(NO3)2(aq) + H2(g) What physical state does (aq) repres
November 2021, Paper 1 Foundation, Q16(c)(i) (2 marks): The student uses the balance to record the change in mass during the reaction. The mass decreases. Explain why. [2]
November 2021, Paper 2 Foundation, Q10 (1 mark): Copper carbonate, CuCO3, decomposes when heated. Copper oxide, CuO, and carbon dioxide gas are made. CuCO3 CuO + CO2 12.4 g of copper carbonate decomposes to ma
November 2021, Paper 2 Foundation, Q18(h) (4 marks): Potassium nitrate, KNO3, is another fertiliser. Potassium nitrate is made by reacting potassium hydroxide, KOH, with nitric acid, HNO3. KOH + HNO3 KNO3 + H2O Ca
November 2021, Paper 3 Higher, Q9 (1 mark): Sodium reacts with hydrochloric acid to give sodium chloride and hydrogen gas. What is the balanced symbol equation for this reaction? A Na + HCl NaCl + H B Na
November 2021, Paper 3 Higher, Q11 (1 mark): The empirical formula of a hydrocarbon is CH2. The relative formula mass of the hydrocarbon is 126.0. What is the molecular formula of the hydrocarbon? A C7H14
November 2021, Paper 3 Higher, Q12 (1 mark): Magnesium reacts with oxygen. Magnesium oxide is made. The balanced symbol equation is shown. 2Mg + O2 2MgO Calculate how much magnesium is needed to make 10.0
November 2021, Paper 3 Higher, Q18(a) (1 mark): State the law of conservation of mass. [1]
November 2021, Paper 3 Higher, Q18(c)(i) (2 marks): Explain why the mass on the balance decreases as the reaction occurs. Use ideas about the particle model in your answer. [2]
November 2021, Paper 3 Higher, Q19(b)(i) (3 marks): Calculate the average mass of one atom of neon, Ne. The Avogadro constant has a value of 6.02 × 1023. Give your answer to 3 significant figures. Average mass of
November 2021, Paper 3 Higher, Q19(b)(iii) (2 marks): Calculate how many moles of neon there are in 101 g of neon. (The relative atomic mass, Ar, of Ne is 20.2.) Moles of neon = mol [2]
November 2021, Paper 3 Higher, Q22(b) (3 marks): Calculate the mass of sulfur dioxide made from 102.3 g of hydrogen sulfide. (The relative atomic mass, Ar, of H is 1.0, of O is 16.0 and of S is 32.1). Mass of
November 2021, Paper 4 Higher, Q19(d) (4 marks): Iron reacts with chlorine to form iron chloride. Look at the equation for the reaction. 2Fe + 3Cl 2 2FeCl 3 Calculate the mass of iron chloride that can be made
November 2020, Paper 1 Foundation, Q3 (1 mark): Look at the balanced symbol equation. CaCO3(s) + 2HCl (aq) CaCl 2(aq) + H2O(l) + CO2(g) What does the symbol (s) represent in the balanced symbol equation? A So
November 2020, Paper 1 Foundation, Q4 (1 mark): The formula of magnesium chloride is MgCl 2. What is the relative formula mass of magnesium chloride? (Ar: Mg = 24.3, Cl = 35.5) A 59.8 B 95.3 C 119.6 D 84.1 Yo
November 2020, Paper 1 Foundation, Q7 (1 mark): Butane has the molecular formula C4H10. What is the empirical formula of butane? A CH5 B C2H5 C C4H10 D CH14 Your answer [1]
November 2020, Paper 1 Foundation, Q9 (1 mark): Ethanol, C2H5OH, burns in oxygen. Carbon dioxide and water are made. Which equation for this reaction is correctly balanced? A C2H5OH + O2 CO2 + H2O B C2H5OH +
November 2020, Paper 1 Foundation, Q13 (1 mark): Oxygen reacts with 1.20 g of carbon. 4.40 g of carbon dioxide forms. C + O2 CO2 What mass of oxygen is used in this reaction? A 0.80 g B 1.60 g C 3.20 g D 5.60
November 2020, Paper 1 Foundation, Q19(b) (2 marks): The burning of methane gas is an exothermic reaction. When methane, CH4, burns in oxygen, O2, carbon dioxide, CO2, and water, H2O, are made. Write the balanced
November 2020, Paper 1 Foundation, Q21(b) (3 marks): The student finds out that phosphate fertilisers are used to help to grow flowers. Compound A is a fertiliser of a metal M with the formula M3PO4. The relative
November 2020, Paper 2 Foundation, Q24(c)(i) (3 marks): Calculate the mass of ammonium nitrate that could be made from 25.5 tonnes of ammonia. Ar: H = 1.0, N = 14.0, O = 16.0 Mass of ammonium nitrate = tonnes [3]
November 2020, Paper 3 Higher, Q1 (1 mark): The formula of ammonium carbonate is (NH4)2CO3. What is the relative formula mass of ammonium carbonate? (Ar: C = 12, H = 1, N = 14, O = 16) A 78 B 90 C 96 D 12
November 2020, Paper 3 Higher, Q3 (1 mark): Magnesium reacts with chlorine. Magnesium chloride is made. What is the balanced symbol equation for this reaction? A Mg + Cl MgCl B Mg + Cl 2 MgCl 2 C 2Mg + Cl
November 2020, Paper 3 Higher, Q10 (1 mark): Avogadro’s constant has a value of 6.02 × 1023. What is the number of atoms in 0.5 mol of water? 2.00 × 1023 A 3.01 × 1023 B 6.02 × 1023 C 9.03 × 1023 D Your an
November 2020, Paper 3 Higher, Q12 (1 mark): Sodium hydroxide reacts with hydrochloric acid. Sodium chloride and water are made. NaOH + HCl NaCl + H2O What mass of sodium hydroxide would be needed to make
November 2020, Paper 3 Higher, Q14 (1 mark): The accurate relative atomic mass of aluminium is 26.9815385. What is this number to 5 significant figures? A 26.98153 B 26.981 C 26.98154 D 26.982 Your answer
November 2020, Paper 3 Higher, Q18(a)(i) (2 marks): Write the balanced symbol equation for this reaction. [2]
November 2020, Paper 3 Higher, Q19(b) (3 marks): After testing the soil samples, the farmer finds that the soil in one of his fields is acidic. Acidic soil can be neutralised by spreading magnesium carbonate,
November 2020, Paper 3 Higher, Q21(b)(i) (3 marks): Sodium oxide reacts with water. An aqueous solution of sodium hydroxide is made. Write the balanced symbol equation for this reaction, including state symbols.
November 2020, Paper 3 Higher, Q22(a)(i) (4 marks): Plot a graph of the student’s results and draw a line of best fit. [4]
November 2020, Paper 3 Higher, Q22(a)(ii) (1 mark): What is the mass of copper carbonate that needs to be heated to produce 2.50 g of copper oxide? Use your graph in your answer. Mass of copper carbonate = g [1]
November 2020, Paper 3 Higher, Q22(a)(iii) (1 mark): The mass of copper oxide made in the reaction is less than the mass of the copper carbonate heated. Suggest why. [1]
November 2020, Paper 3 Higher, Q22(b) (4 marks): Calcium carbonate thermally decomposes to make calcium oxide and carbon dioxide. CaCO3 CaO + CO2 Calculate the mass of calcium carbonate needed to make 209 g of
November 2020, Paper 4 Higher, Q17(c)(i) (3 marks): Calculate the mass of ammonium nitrate that could be made from 25.5 tonnes of ammonia. Ar: H = 1.0, N = 14.0, O = 16.0 Mass of ammonium nitrate = tonnes [3]
November 2020, Paper 4 Higher, Q22(b)(ii) (1 mark): Use your answer from (b)(i) to calculate the mass of hydrogen gas produced. Mass of hydrogen gas = g [1]
November 2020, Paper 4 Higher, Q22(c) (3 marks): Chromium metal, Cr, reacts with nickel sulfate solution, NiSO4. Solid nickel is made. Two possible equations for this reaction are: Equation 1 Cr + NiSO4 CrSO4
June 2019, Paper 1 Foundation, Q2 (1 mark): A student reacts calcium carbonate with hydrochloric acid. CaCO3(s) + 2HCl (aq) CaCl 2(aq) + H2O(l) + CO2(g) What physical state does (g) represent in the balan
June 2019, Paper 1 Foundation, Q5 (1 mark): The formula of sulfuric acid is H2SO4. What is the relative formula mass, Mr, of sulfuric acid? The relative atomic mass, Ar, of H is 1, of S is 32 and of O is
June 2019, Paper 1 Foundation, Q6 (1 mark): Which of these is a physical change? A Burning wood B Melting wax C Neutralising an acid D Rusting iron Your answer [1]
June 2019, Paper 1 Foundation, Q13 (1 mark): The molecular formula of hydrogen peroxide is H2O2. What is the empirical formula of hydrogen peroxide? A H2O2 B H2O C HO D H2O4 Your answer [1]
June 2019, Paper 1 Foundation, Q16(c) (2 marks): The student heated the mixture to form solid iron sulfide. This is an example of a chemical change. Write down two ways the student will know a chemical reactio
June 2019, Paper 1 Foundation, Q19(a)(ii) (2 marks): The metal magnesium reacts with hydrochloric acid, HCl , to form magnesium chloride, MgCl 2, and hydrogen. Write a balanced symbol equation for this reaction. [
June 2019, Paper 2 Foundation, Q21(a) (2 marks): Write the balanced symbol equation for this reaction. [2]
June 2019, Paper 3 Higher, Q10 (1 mark): Avogadro’s constant has a value of 6.02 × 1023. How many oxygen atoms are in 0.25 moles of oxygen molecules? 1.204 × 1024 A 1.505 × 1023 B 3.010 × 1023 C 6.020
June 2019, Paper 3 Higher, Q11 (1 mark): Methane burns in oxygen to form carbon dioxide and water. CH4 + 2O2 CO2 + 2H2O Calculate the amount of carbon dioxide made when 6.4 g of methane is burnt. A 2.8
June 2019, Paper 3 Higher, Q13 (1 mark): 2−? 13 What is the amount, in mol, of 15 g of carbonate ions, CO3 A 0.18 B 0.25 C 4.0 D 5.6 Your answer [1]
June 2019, Paper 3 Higher, Q19(c)(iii) (2 marks): Barium chloride solution reacts with sodium sulfate solution, Na2SO4. A white precipitate of barium sulfate, BaSO4, is made. Write a balanced ionic equation to
June 2019, Paper 3 Higher, Q22(b)(i) (2 marks): Solid lead reacts with nitric acid, HNO3. Lead nitrate, Pb(NO3)2, nitrogen oxide, NO, and water are made. Write a balanced symbol equation for this reaction. [2
June 2019, Paper 3 Higher, Q22(b)(ii) (4 marks): How many moles of lead nitrate would be produced if 20.7 g of lead reacts with nitric acid? Give your answer to 2 significant figures. Moles of lead nitrate = [
June 2019, Paper 4 Higher, Q19(a) (2 marks): Write the balanced symbol equation for this reaction. [2]
June 2019, Paper 4 Higher, Q22(a) (2 marks): In an experiment, a mixture of ammonium chloride and calcium hydroxide is heated. Ammonia gas, NH3, is made. 2NH4Cl + Ca(OH)2 CaCl 2 + 2NH3 + 2H2O A student add
June 2018, Paper 1 Foundation, Q17(a) (2 marks): Complete the table to show the number of atoms of each element in this displayed formula. Element Number of atoms C H O [2]
June 2018, Paper 1 Foundation, Q17(b) (1 mark): What is the empirical formula of succinic acid? [1]
June 2018, Paper 1 Foundation, Q19(a) (1 mark): What is the meaning of (s) in the equation? [1]
June 2018, Paper 1 Foundation, Q19(b) (1 mark): Look at their results. Mass of calcium carbonate Mass of calcium oxide Mass of carbon dioxide (g) (g) (g) 1.00 0.56 0.44 2.00 1.12 0.88 3.00 1.68 1.32 4.00 2.24
June 2018, Paper 1 Foundation, Q19(c) (2 marks): Student A states: ‘If I heat 20 g of calcium carbonate, I will make 8.8 g of calcium oxide and 11.2 g of carbon dioxide.’ Is student A correct? Explain your ans
June 2018, Paper 1 Foundation, Q19(d)(i) (1 mark): Calculate the relative formula mass of magnesium oxide. Answer = [1]
June 2018, Paper 1 Foundation, Q19(d)(ii) (2 marks): Use the relative formula mass of magnesium oxide and the relative atomic masses of magnesium and oxygen to show if mass is conserved during this reaction. [2]
June 2018, Paper 1 Foundation, Q25(b) (2 marks): Magnesium reacts with water. Magnesium hydroxide, Mg(OH)2, and hydrogen, H2, are made. Write a balanced symbol equation for this reaction. [2]
June 2018, Paper 1 Foundation, Q25(c) (1 mark): Magnesium nitrate has the formula Mg(NO3)2. Calculate the relative formula mass of magnesium nitrate. Answer = [1]
June 2018, Paper 2 Foundation, Q8 (1 mark): Hydrogen gas can be made by reacting methane and steam (H2O). CH4 + H2O 3H2 + CO 6 g of hydrogen gas can be made from 18 g of steam, H2O. How much hydrogen gas
June 2018, Paper 2 Foundation, Q18(a) (2 marks): Write a balanced symbol equation for this reaction. [2]
June 2018, Paper 3 Higher, Q16(b) (2 marks): Magnesium reacts with water. Magnesium hydroxide, Mg(OH)2, and hydrogen, H2, are made. Write a balanced symbol equation for this reaction. [2]
June 2018, Paper 3 Higher, Q16(c) (1 mark): Magnesium nitrate has the formula Mg(NO3)2. Calculate the relative formula mass of magnesium nitrate. Answer = [1]
June 2018, Paper 3 Higher, Q18(c) (2 marks): Propane burns in oxygen, O2. Carbon dioxide and water are made. Write a balanced symbol equation for this reaction. [2]
June 2018, Paper 3 Higher, Q26(a) (1 mark): What is meant by the Avogadro constant? [1]
June 2018, Paper 3 Higher, Q26(b) (3 marks): Calculate the number of water molecules in 72 g of water, H2O. Give your answer to 3 significant figures. Answer = [3]
June 2018, Paper 3 Higher, Q26(c) (4 marks): A student is reacting magnesium oxide with nitric acid. Look at the equation for the reaction. MgO + 2HNO3 Mg(NO3)2 + H2O The student wants to make 14.8 g of ma
June 2018, Paper 4 Higher, Q18(a) (2 marks): Write a balanced symbol equation for the reaction. [2]
June 2018, Paper 4 Higher, Q21(b)(i) (2 marks): Calculate the amount of hydrogen gas, in mol, that could be made from 3.27 g of zinc. Answer = mol [2]

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