Formulas — Paper 1 · IGCSE Sciences - Co-ordinated (Double) 0654

15 The metal titanium occurs naturally combined with oxygen. The table shows the combining powers of the elements in this compound. element symbol combining power oxygen O 2 titanium Ti 4 What could be the formula of the compound? A TiO2 B Ti2O C TiO4 D Ti4O2

1 marks

Answer: A

This question in 0654/11 May/June 2008

24 Fertilisers are used to supply the essential elements needed for plant growth. Which compound supplies two of these essential elements? A Ca(H2PO4)2 B Ca(NO3)2 C KNO3 D (NH4)2SO4

1 marks

Answer: C

This question in 0654/11 May/June 2008

14 The element phosphorus burns in air, as shown. 4P + 5O2 → P4O10 What does the formula P4O10 show? A a mixture of atoms of two elements B a mixture of molecules of two elements C a molecule of a compound D an atom of a compound

1 marks

Answer: C

This question in 0654/11 May/June 2009

16 How many atoms of metals and of non-metals are shown in the formula Na2SO4? atoms of atoms of metals non-metals A 1 1 B 1 2 C 2 4 D 2 5

1 marks

Answer: C

This question in 0654/11 May/June 2012

25 Fertilisers are used to supply the essential elements needed for plant growth. Which compound supplies two of these essential elements? A Ca(H2PO4)2 B Ca(NO3)2 C KNO3 D (NH4)2SO4

1 marks

Answer: C

This question in 0654/11 May/June 2012

16 Which formula contains the most elements? A NaOH B Rb2S C SiCl 4 D SnO2

1 marks

Answer: A

This question in 0654/13 May/June 2012

27 The diagram represents the arrangement of atoms in a molecule of a compound. key carbon atom hydrogen atom What is the molecular formula of the compound? A CH2 B C3H6 C C3H8 D C6H3

1 marks

Answer: B

This question in 0654/11 May/June 2013

15 A model of a molecule is shown. key hydrogen atom boron atom Which row shows the formula and describes the bonding in this molecule? formula bonding A 2BH3 covalent B 2BH3 ionic C B2H6 covalent D B2H6 ionic

1 marks

Answer: C

This question in 0654/12 May/June 2013

27 The diagram represents the arrangement of atoms in a molecule of a compound. key carbon atom hydrogen atom What is the molecular formula of the compound? A CH2 B C3H6 C C3H8 D C6H3

1 marks

Answer: B

This question in 0654/13 May/June 2013

16 Nitrogen and hydrogen react to form ammonia. key = N + = H How many molecules of ammonia are formed from 3 molecules of nitrogen, N2? A 2 B 3 C 6 D 12

1 marks

Answer: C

This question in 0654/12 May/June 2014

18 Hydrogen peroxide is a compound. A molecule of hydrogen peroxide can be represented as shown. key = oxygen = hydrogen What is the correct formula of hydrogen peroxide? A HO B H2O2 C (OH)2 D 2OH

1 marks

Answer: B

This question in 0654/13 Oct/Nov 2014

14 The structures of some substances are shown. water ethanol methane Which row shows the total number of different elements and the total number of atoms in the three structures? total total number of number of different atoms elements A 3 9 B 3 17 C 7 9 D 7 17

1 marks

Answer: B

This question in 0654/12 Oct/Nov 2015

16 Phosphoric acid is a compound containing three hydrogen atoms, one phosphorous atom and four oxygen atoms. What is the formula of phosphoric acid? A 3HP4O B 3HPO4 C H3P4O D H3PO4

1 marks

Answer: D

This question in 0654/12 May/June 2016

16 A model of a molecule is shown. key hydrogen atom boron atom Which row shows the formula of this molecule and describes the type of bonding between the atoms? formula bonding A 2BH3 covalent B 2BH3 ionic C B2H6 covalent D B2H6 ionic

1 marks

Answer: C

This question in 0654/11 Oct/Nov 2016

16 A model of a molecule is shown. key hydrogen atom boron atom Which row shows the formula of this molecule and describes the type of bonding between the atoms? formula bonding A 2BH3 covalent B 2BH3 ionic C B2H6 covalent D B2H6 ionic

1 marks

Answer: C

This question in 0654/12 Oct/Nov 2016

16 A model of a molecule is shown. key hydrogen atom boron atom Which row shows the formula of this molecule and describes the type of bonding between the atoms? formula bonding A 2BH3 covalent B 2BH3 ionic C B2H6 covalent D B2H6 ionic

1 marks

Answer: C

This question in 0654/13 Oct/Nov 2016

15 How many atoms of metals and of non-metals are shown in the formula Na2SO4? atoms of atoms of metals non-metals A 1 1 B 1 2 C 2 4 D 2 5

1 marks

Answer: D

This question in 0654/11 May/June 2017

16 How many atoms of metals and of non-metals are shown in the formula Na2SO4? atoms of atoms of metals non-metals A 1 1 B 1 2 C 2 4 D 2 5

1 marks

Answer: D

This question in 0654/12 May/June 2017

15 How many atoms of metals and of non-metals are shown in the formula Na2SO4? atoms of atoms of metals non-metals A 1 1 B 1 2 C 2 4 D 2 5

1 marks

Answer: D

This question in 0654/13 May/June 2017

17 Cryolite is a mineral which contains aluminium, sodium and fluorine. It contains twice as many fluorine atoms as sodium atoms. It contains three times as many sodium atoms as aluminium atoms. What is the formula of cryolite? A NaAl 3F6 B Na2Al F4 C Na3Al F6 D Na3Al F4

1 marks

Answer: C

This question in 0654/12 Oct/Nov 2018

17 Hydrogen peroxide is a compound. A molecule of hydrogen peroxide can be represented as shown. key = oxygen = hydrogen What is the formula of hydrogen peroxide? A HO B H2O2 C (OH)2 D 2OH

1 marks

Answer: B

This question in 0654/11 Oct/Nov 2019

17 Hydrogen peroxide is a compound. A molecule of hydrogen peroxide can be represented as shown. key = oxygen = hydrogen What is the formula of hydrogen peroxide? A HO B H2O2 C (OH)2 D 2OH

1 marks

Answer: B

This question in 0654/12 Oct/Nov 2019

16 Hydrogen peroxide is a compound. A molecule of hydrogen peroxide can be represented as shown. key = oxygen = hydrogen What is the formula of hydrogen peroxide? A HO B H2O2 C (OH)2 D 2OH

1 marks

Answer: B

This question in 0654/13 Oct/Nov 2019

15 Copper hydroxide contains one copper atom, two hydrogen atoms and two oxygen atoms. What is the correct formula of copper hydroxide? A CuH2O2 B CuO2H2 C Cu(OH)2 D H2O2Cu

1 marks

Answer: C

This question in 0654/12 Feb/March 2021

14 The structures of some substances are shown. water ethanol methane Which row shows the total number of different elements and the total number of atoms in the three structures? total total number of number of different atoms elements A 3 9 B 3 17 C 7 9 D 7 17

1 marks

Answer: B

This question in 0654/11 May/June 2021

14 The structures of some substances are shown. water ethanol methane Which row shows the total number of different elements and the total number of atoms in the three structures? total total number of number of different atoms elements A 3 9 B 3 17 C 7 9 D 7 17

1 marks

Answer: B

This question in 0654/12 May/June 2021

14 The structures of some substances are shown. water ethanol methane Which row shows the total number of different elements and the total number of atoms in the three structures? total total number of number of different atoms elements A 3 9 B 3 17 C 7 9 D 7 17

1 marks

Answer: B

This question in 0654/13 May/June 2021

16 A model of a molecule is shown. key hydrogen atom boron atom Which row shows the formula of this molecule and describes the type of bonding between the atoms? formula bonding A 2BH3 covalent B 2BH3 ionic C B2H6 covalent D B2H6 ionic

1 marks

Answer: C

This question in 0654/11 Oct/Nov 2021

16 A model of a molecule is shown. key hydrogen atom boron atom Which row shows the formula of this molecule and describes the type of bonding between the atoms? formula bonding A 2BH3 covalent B 2BH3 ionic C B2H6 covalent D B2H6 ionic

1 marks

Answer: C

This question in 0654/12 Oct/Nov 2021

16 A model of a molecule is shown. key hydrogen atom boron atom Which row shows the formula of this molecule and describes the type of bonding between the atoms? formula bonding A 2BH3 covalent B 2BH3 ionic C B2H6 covalent D B2H6 ionic

1 marks

Answer: C

This question in 0654/13 Oct/Nov 2021

15 Propene, C3H6, burns in excess oxygen to form carbon dioxide and water. wC3H6 + xO2  yCO2 + zH2O Which values of w, x, y and z balance this equation? w x y z A 1 9 3 3 B 1 5 3 6 C 2 9 6 6 D 2 5 6 3

1 marks

Answer: C

This question in 0654/12 Feb/March 2022

16 Propanol, CH3CH2CH2OH, burns in oxygen to produce carbon dioxide and water. 2CH3CH2CH2OH + 9O2  xCO2 + yH2O Which values of x and y balance the equation? x y A 3 4 B 3 8 C 6 4 D 6 8

1 marks

Answer: D

This question in 0654/11 May/June 2022

16 Which equation is balanced? A 2H2 + O2  2H2O2 B MgO + 2H2SO4  MgSO4 + 2H2O C Na + H2O  NaOH + H2 D Na2CO3 + 2HCl  2NaCl + H2O + CO2

1 marks

Answer: D

This question in 0654/12 May/June 2022

16 Which equation is balanced? A 2H2 + O2  2H2O2 B MgO + 2H2SO4  MgSO4 + 2H2O C Na + H2O  NaOH + H2 D Na2CO3 + 2HCl  2NaCl + H2O + CO2

1 marks

Answer: D

This question in 0654/13 May/June 2022

16 Hydrogen reacts with oxygen to produce water. What is the balanced equation for this reaction? A H2 + O2  H2O B H2 + O2  2H2O C H2 + O  H2O D 2H2 + O2  2H2O

1 marks

Answer: D

This question in 0654/11 Oct/Nov 2022

16 There are three times as many hydrogen atoms as carbon atoms in one molecule of hydrocarbon X. What is the formula of X? A CH4 B C2H4 C C2H6 D C2H5OH

1 marks

Answer: C

This question in 0654/12 Oct/Nov 2022

17 The structures of some compounds are shown. structure formula H H 1 H C C O H C2H6O H H 2 C=O CO2 O 3 HNO3 H O N O 4 O=S=O SO4 In which rows does the formula match the structure? A 1 and 2 B 1 and 3 C 2 and 4 D 3 and 4

1 marks

Answer: B

This question in 0654/12 May/June 2023

17 The structures of some compounds are shown. structure formula H H 1 H C C O H C2H6O H H 2 C=O CO2 O 3 HNO3 H O N O 4 O=S=O SO4 In which rows does the formula match the structure? A 1 and 2 B 1 and 3 C 2 and 4 D 3 and 4

1 marks

Answer: B

This question in 0654/13 May/June 2023

17 The diagram represents an ionic compound formed from three types of atom. key oxygen sodium sulfur What is the chemical formula for this compound? A Na2S4O B NaO4S2 C Na2SO4 D S4O2Na

1 marks

Answer: C

This question in 0654/11 Oct/Nov 2023

16 Which equation represents the reaction between aluminium and oxygen? A 2Al + 3O  Al 2O3 B Al 2 + 3O  Al 2O3 C 2Al 2 + 3O2  2Al 2O3 D 4Al + 3O2  2Al 2O3

1 marks

Answer: D

This question in 0654/12 Oct/Nov 2023

17 Dilute hydrochloric acid reacts with sodium carbonate to form sodium chloride, carbon dioxide and water. The equation for the reaction is shown. w HCl + Na2CO3  x NaCl + y CO2 + z H2O What are the values of w, x, y and z? w x y z A 1 1 3 1 B 2 1 1 1 C 2 2 3 2 D 2 2 1 1

1 marks

Answer: D

This question in 0654/13 Oct/Nov 2023

17 Hydrogen peroxide is a compound. A molecule of hydrogen peroxide can be represented as shown. key = oxygen atom = hydrogen atom What is the formula of hydrogen peroxide? A HO B H2O2 C H2O D 2OH

1 marks

Answer: B

This question in 0654/11 May/June 2024

17 Which oxides of nitrogen have the same ratio of nitrogen atoms to oxygen atoms? 1 N2O 2 NO 3 NO2 4 N2O4 A 1 and 2 B 1 and 3 C 2 and 4 D 3 and 4

1 marks

Answer: D

This question in 0654/12 May/June 2024

17 Which oxides of nitrogen have the same ratio of nitrogen atoms to oxygen atoms? 1 N2O 2 NO 3 NO2 4 N2O4 A 1 and 2 B 1 and 3 C 2 and 4 D 3 and 4

1 marks

Answer: D

This question in 0654/13 May/June 2024

16 Which formula contains the most elements? A NaOH B Rb2S C SiCl 4 D SnO2

1 marks

Answer: A

This question in 0654/12 Oct/Nov 2024

16 Which formula contains the most elements? A NaOH B Rb2S C SiCl 4 D SnO2

1 marks

Answer: A

This question in 0654/13 Oct/Nov 2024

20 A piece of magnesium ribbon is placed in dilute hydrochloric acid. The magnesium reacts and bubbles of a colourless gas are formed. What is the word equation for this reaction? A magnesium + hydrochloric acid  magnesium chloride + hydrogen B magnesium + hydrochloric acid  magnesium chloride + carbon dioxide + water C magnesium + hydrochloric acid  magnesium chloride + carbon dioxide D magnesium + hydrochloric acid  magnesium chloride + hydrogen + water

1 marks

Answer: A

This question in 0654/13 Oct/Nov 2024

18 Magnesium hydroxide contains twice as many atoms of both oxygen and hydrogen than atoms of magnesium. What is the formula of magnesium hydroxide? A MgOH B MgO2H2 C Mg(OH)2 D Mg2(OH)

1 marks

Answer: C

This question in 0654/12 Feb/March 2025