Formulae — Paper 2 · IGCSE Chemistry (9-1) 0971

9 The formulae of some ions are shown. positive ion negative ion Ti4+ PO4 3– Al 3+ SO4 2– Mg2+ NO3 – K+ Cl – Which formula is not correct? A Al 3(SO4)2 B K3PO4 C Mg(NO3)2 D TiCl 4

1 marks

Answer: A

This question in 0971/22 Oct/Nov 2018

7 Propane burns in oxygen. C3H8 + xO2 → 3CO2 + yH2O Which values of x and y balance the equation? x y A 5 4 B 7 4 C 10 8 D 13 8

1 marks

Answer: A

This question in 0971/21 May/June 2019

8 Lead(II) nitrate, Pb(NO3)2, reacts with potassium iodide, KI, to form a yellow precipitate, PbI2, and a soluble salt, KNO3. What is the equation for the reaction? A Pb(NO3)2 + KI → PbI2 + KNO3 B Pb(NO3)2 + 2KI → PbI2 + KNO3 C 2Pb(NO3)2 + 2KI → PbI2 + 2KNO3 D Pb(NO3)2 + 2KI → PbI2 + 2KNO3

1 marks

Answer: D

This question in 0971/22 May/June 2020

8 Ethyl methanoate, HCOOC2H5, burns in excess oxygen to produce carbon dioxide and water. The equation is shown. 2HCOOC2H5 + xO2  6CO2 + 6H2O What is the value of x? A 2 B 7 C 9 D 18

1 marks

Answer: B

This question in 0971/22 Oct/Nov 2020

11 A reaction involving aluminium is shown. xAl + yO2 + 6H2O  xAl (OH)3 Which values of x and y balance the equation? x y A 2 3 B 3 2 C 3 4 D 4 3

1 marks

Answer: D

This question in 0971/22 May/June 2021

7 The equation for the reaction between barium chloride and dilute sulfuric acid is shown. BaCl 2 + H2SO4  BaSO4 + 2HCl Which row shows the state symbols for this equation? BaCl 2 H2SO4 BaSO4 2HCl A (aq) (aq) (s) (aq) B (aq) (l) (s) (aq) C (l) (aq) (s) (l) D (aq) (l) (aq) (l)

1 marks

Answer: A

This question in 0971/21 May/June 2022

7 The equation for the reaction between barium chloride and dilute sulfuric acid is shown. BaCl 2 + H2SO4  BaSO4 + 2HCl Which row shows the state symbols for this equation? BaCl 2 H2SO4 BaSO4 2HCl A (aq) (aq) (s) (aq) B (aq) (l) (s) (aq) C (l) (aq) (s) (l) D (aq) (l) (aq) (l)

1 marks

Answer: A

This question in 0971/22 May/June 2022

7 Which formula is an empirical formula? A C2H4O B C4H8O2 C C3H7COOH D CH3CH2CH2COOH

1 marks

Answer: A

This question in 0971/21 May/June 2023

8 The concentration of a sample of dilute aqueous sodium hydroxide is found by titration. The apparatus used is shown. dilute aqueous hydrochloric acid, HCl(aq) dilute aqueous sodium hydroxide, NaOH(aq) Which information is needed to calculate the concentration of the dilute aqueous sodium hydroxide in mol/dm?? concentration volume of molar mass volume of molar mass of HCl HCl used of HCl NaOH used of NaOH Jv Jv Jv Jv Jv v v x v x x v v v x v x x x v key Jv = needed X =not needed

1 marks

Answer: B

This question in 0971/22 May/June 2023

8 A hydrocarbon contains 85.7% of carbon by mass. What is the empirical formula of the hydrocarbon? A CH2 B CH4 C C2H5 D C3H6

1 marks

Answer: A

This question in 0971/22 Oct/Nov 2023

11 What is the empirical formula of ethanoic acid? A CHO B CH2O C C2H2O D C2H4O2

1 marks

Answer: B

This question in 0971/21 May/June 2024

7 The structure of glycine is shown. H H O N C C H H O H Which row is correct? number of different formula of glycine elements in glycine A CH5O2N 10 B C2H5O2N 4 C C2H5O2N 10 D H2NCHCOOH 4

1 marks

Answer: B

This question in 0971/22 May/June 2024

8 The incomplete equation for photosynthesis is shown. wCO2 + xH2O →P + yO2 Compound P is a product of the reaction. Which row describes the values of w, x and y and gives the empirical formula of compound P? empirical formula values of w, x and y of compound P A w, x and y are all the same CH2O B w, x and y are all the same C6H12O6 C w and x are the same and both are greater than y CH2O D w and x are the same and both are greater than y C6H12O6

1 marks

Answer: A

This question in 0971/22 May/June 2024

11 What is the empirical formula of a compound that contains 3.66 g of hydrogen, 37.8 g of phosphorus and 58.5 g of oxygen? A H6P2O6 B H4PO4 C H3PO3 D HPO

1 marks

Answer: C

This question in 0971/22 Oct/Nov 2024

8 Aluminium reacts with iron(III) oxide to form aluminium oxide and iron. Which chemical equation for the reaction between aluminium and iron(III) oxide is correct? A Al + FeO  Al O + Fe B 2Al + Fe2O  Al 2O + 2Fe C Al + Fe2O3  Al 2O3 + Fe D 2Al + Fe2O3  Al 2O3 + 2Fe

1 marks

Answer: D

This question in 0971/22 May/June 2025

10 The equation for the combustion of ethanol is shown. C2H5OH + 3O2  2CO2 + 3H2O The relative molecular mass, Mr, of ethanol is 46. Which statement about the reaction is correct? A 4.6 g of ethanol produces 4.4 g of carbon dioxide. B 92 g of ethanol produces 88 g of carbon dioxide and 108 g of water. C 138 g of ethanol reacts with 32 g of oxygen. D 184 g of ethanol produces 216 g of water.

1 marks

Answer: D

This question in 0971/22 Oct/Nov 2025

11 A compound contains 40.0% carbon, 6.7% hydrogen and 53.3% oxygen only. The relative molecular mass, Mr, of the compound is 60. Which row shows the empirical formula and the molecular formula of the compound? empirical formula molecular formula A CH2O CH2O B CH2O C2H4O2 C C3H7O3 C3H7O3 D C3H8O C3H8O

1 marks

Answer: B

This question in 0971/22 Oct/Nov 2025