Formulas — Paper 1 · A Level Chemistry 9701

30 The ester CH3CH2CH2CO2CH3 is responsible for the aroma of apples. When this ester is hydrolysed by acid in the stomach, what is the empirical formula of the organic acid produced? A CH4O B C2H4O C C2H4O2 D C3H7O2

1 marks

Answer: B

This question in 9701/11 Oct/Nov 2007

1 Use of the Data Booklet is relevant to this question. In leaded petrol there is an additive composed of lead, carbon and hydrogen only. This compound contains 29.7 % carbon and 6.19 % hydrogen by mass. What is the value of x in the empirical formula PbC8HX? A 5 B 6 C 16 D 20

1 marks

Answer: D

This question in 9701/11 May/June 2009

2 0.200 mol of a hydrocarbon undergo complete combustion to give 35.2 g of carbon dioxide and 14.4 g of water as the only products. What is the molecular formula of the hydrocarbon? A C2H4 B C2H6 C C4H4 D C4H8

1 marks

Answer: D

This question in 9701/11 Oct/Nov 2009

6 Which ion has more electrons than protons and more protons than neutrons? [H = 1 1H ; D = 2 1 H ; O = 16 8 O] A D– B H3O+ C OD– D OH–

1 marks

Answer: D

This question in 9701/11 Oct/Nov 2010

12 Camphor is a white solid which was used to make the early plastic celluloid. Camphor contains the same percentage by mass of hydrogen and oxygen. What is the molecular formula of camphor? A C10H6O6 B C10H8O C C10H16O D C10H10O2

1 marks

Answer: C

This question in 9701/11 Oct/Nov 2010

38 Organic acids and alcohols react together to form esters. Which pairs of compounds could produce a product of molecular formula C4H6O4? 1 CH3CO2H and C2H5OH 2 HCO2H and HOCH2CH2OH 3 HO2CCO2H and CH3OH

1 marks

Answer: C

This question in 9701/12 Oct/Nov 2010

14 Camphor is a white solid which was used to make the early plastic celluloid. Camphor contains the same percentage by mass of hydrogen and oxygen. What is the molecular formula of camphor? A C10H6O6 B C10H8O C C10H16O D C10H10O2

1 marks

Answer: C

This question in 9701/13 Oct/Nov 2010

17 Ammonium nitrate, NH4NO3, is manufactured in large quantities for use in fertiliser. Which statement about ammonium nitrate fertiliser is not correct? A It can cause environmental problems. B It consists of 35 % nitrogen by mass. C It is insoluble in water. D Nitric acid is used in its manufacture.

1 marks

Answer: C

This question in 9701/11 May/June 2011

10 Tanzanite is used as a gemstone for jewellery. It is a hydrated calcium aluminium silicate mineral with a chemical formula Ca2Al xSiyO12(OH).6½H2O. Tanzanite has Mr of 571.5. Its chemical composition is 14.04 % calcium, 14.17 % aluminium, 14.75 % silicon, 54.59 % oxygen and 2.45 % hydrogen. (Ar values: H = 1.0, O = 16.0, Al = 27.0, Si = 28.1, Ca = 40.1) What are the values of x and y? x y A 1 1 B 2 3 C 3 3 D 6 1

1 marks

Answer: C

This question in 9701/12 May/June 2011

40 An organic compound, X, will react with an excess of calcium metal to produce a salt with the empirical formula CaC4H6O4. What could be the identity of X? 1 ethanoic acid 2 butanedioic acid 3 methylpropanedioic acid

1 marks

Answer: D

This question in 9701/12 May/June 2011

18 Ammonium nitrate, NH4NO3, is manufactured in large quantities for use in fertiliser. Which statement about ammonium nitrate fertiliser is not correct? A It can cause environmental problems. B It consists of 35 % nitrogen by mass. C It is insoluble in water. D Nitric acid is used in its manufacture.

1 marks

Answer: C

This question in 9701/13 May/June 2011

11 Two moles of compound P were placed in a vessel. The compound P was partly decomposed by heating. A dynamic equilibrium between chemicals P, Q and R was established. At equilibrium, x mol of R were present and the total number of moles present was (2 + x). What is the equation for this equilibrium? A P 2Q + R B 2P 2Q + R C 2P Q + R D 2P Q + 2R

1 marks

Answer: B

This question in 9701/13 May/June 2012

39 An organic compound, X, will react with calcium metal to produce a salt with the empirical formula CaC4H4O4. What could be the identity of X? 1 ethanoic acid 2 butanedioic acid 3 2-methylpropanedioic acid

1 marks

Answer: C

This question in 9701/13 Oct/Nov 2012

39 The Mr of compound X is 72. The composition by mass of X is 66.7 % carbon, 11.1 % hydrogen and 22.2 % oxygen. X gives an orange precipitate with 2,4-dinitrophenylhydrazine reagent. X does not react with Fehling’s reagent. What can be deduced from this information? 1 X is a carbonyl compound. 2 X is a ketone. 3 X is butanone.

1 marks

Answer: A

This question in 9701/12 May/June 2013

40 An organic compound, Z, will react with calcium metal to produce a salt with the empirical formula CaC4H6O4. What could be the identity of Z? 1 ethanoic acid 2 butanedioic acid 3 methylpropanedioic acid

1 marks

Answer: D

This question in 9701/12 May/June 2013

9 Which formula represents the empirical formula of a compound? A CH4O B C2H4 C C6H12 D H2O2

1 marks

Answer: A

This question in 9701/13 May/June 2013

10 Use of the Data Booklet is relevant to this question. Which sodium compound contains 74.2 % by mass of sodium? A sodium carbonate B sodium chloride C sodium hydroxide D sodium oxide

1 marks

Answer: D

This question in 9701/11 Oct/Nov 2013

10 Use of the Data Booklet is relevant to this question. Which sodium compound contains 74.2 % by mass of sodium? A sodium carbonate B sodium chloride C sodium hydroxide D sodium oxide

1 marks

Answer: D

This question in 9701/12 Oct/Nov 2013

11 Use of the Data Booklet is relevant to this question. Which calcium compound contains 54.1 % by mass of calcium? A calcium hydroxide B calcium nitrate C calcium oxide D calcium sulfate

1 marks

Answer: A

This question in 9701/13 Oct/Nov 2013

20 The diagram shows the skeletal formula of phenazine. N N N N phenazine What is the empirical formula of phenazine? A C6H4N B C6H6N C C12H8N2 D C12H12N2

1 marks

Answer: A

This question in 9701/12 May/June 2014

28 The ester CH3CH2CH2CO2CH3 is responsible for the aroma of apples. When this ester is hydrolysed by acid in the stomach, what is the empirical formula of the organic acid produced? A CH2O B CH4O C C2H4O D C3H6O2

1 marks

Answer: C

This question in 9701/11 Oct/Nov 2014

29 Which equation correctly represents the balanced equation for the complete combustion of a hydrocarbon with the formula CxHy? A y )O2 → xCO2 + 2 y H2O CxHy + (x + 2 B y )O2 → xCO2 + yH2O CxHy + (x + 4 C y )O2 → xCO2 + 4 y H2O CxHy + (x + 4 D y )O2 → xCO2 + 2 y H2O CxHy + (x + 4

1 marks

Answer: D

This question in 9701/11 Oct/Nov 2014

6 Aluminium carbide, Al 4C3, reacts readily with aqueous sodium hydroxide. The two products of the reaction are NaAl O2 and a hydrocarbon. Water molecules are also involved as reactants. What is the formula of the hydrocarbon? A CH4 B C2H6 C C3H8 D C6H12

1 marks

Answer: A

This question in 9701/12 Oct/Nov 2014

28 The ester CH3CH2CH2CO2CH3 is responsible for the aroma of apples. When this ester is hydrolysed by acid in the stomach, what is the empirical formula of the organic acid produced? A CH2O B CH4O C C2H4O D C3H6O2

1 marks

Answer: C

This question in 9701/12 Oct/Nov 2014

29 Which equation correctly represents the balanced equation for the complete combustion of a hydrocarbon with the formula CxHy? A y )O2 → xCO2 + 2 y H2O CxHy + (x + 2 B y )O2 → xCO2 + yH2O CxHy + (x + 4 C y )O2 → xCO2 + 4 y H2O CxHy + (x + 4 D y )O2 → xCO2 + 2 y H2O CxHy + (x + 4

1 marks

Answer: D

This question in 9701/12 Oct/Nov 2014

25 Terpinen-4-ol is one of the active ingredients in tea tree oil. HO terpinen-4-ol What is the molecular formula of terpinen-4-ol? A C7H11O B C10H16O C C10H17O D C10H18O

1 marks

Answer: D

This question in 9701/12 May/June 2015

17 Ammonium sulfate, (NH4)2SO4, and ammonium nitrate, NH4NO3, are used as fertilisers. These salts have different percentages by mass of nitrogen. They have the same effect as each other on the pH of neutral soil. Which row is correct? higher percentage effect on pH of soil of nitrogen by mass A ammonium nitrate decrease B ammonium nitrate increase C ammonium sulfate decrease D ammonium sulfate increase

1 marks

Answer: A

This question in 9701/12 Feb/March 2016

3 Tetraethyl lead, Pb(C2H5)4, has been used as a petrol additive. What is the percentage by mass of carbon in tetraethyl lead? A 10.2 B 14.9 C 29.7 D 32.0

1 marks

Answer: C

This question in 9701/11 May/June 2016

31 In an experiment, 10 cm3 of an organic compound, J, in the gaseous state was sparked with an excess of oxygen. 20 cm3 of carbon dioxide and 5 cm3 of nitrogen were obtained among the products. All gas volumes were measured at the same temperature and pressure. What could be the identity of J? 1 C2H6N2 2 C2H3N 3 C2H7N

1 marks

Answer: C

This question in 9701/12 May/June 2016

37 The diagram shows a compound used as a flame retardant. Br Br Br Br Br Br Which statements about this structure are correct? 1 The empirical formula is C2H3Br. 2 The C12 ring is not planar. 3 There are six chiral carbon atoms.

1 marks

Answer: A

This question in 9701/12 May/June 2016

5 At a temperature of 2500 K and a pressure of 1.00 × 10–4 Pa a sample of 0.321 g of sulfur vapour has a volume of 2.08 × 106 m3. What is the molecular formula of sulfur under these conditions? A S B S2 C S4 D S8

1 marks

Answer: A

This question in 9701/12 May/June 2017

1 Which formula represents the empirical formula of a compound? A C2H4O B C2H4O2 C C6H12 D H2O2

1 marks

Answer: A

This question in 9701/11 Oct/Nov 2017

16 Which fertiliser contains the greatest percentage of nitrogen by mass? A ammonium nitrate, NH4NO3 B ammonium sulfate, (NH4)2SO4 C diammonium hydrogen phosphate, (NH4)2HPO4 D urea, CO(NH2)2

1 marks

Answer: D

This question in 9701/11 Oct/Nov 2017

2 Two hydrocarbons have the formulae CWHX and CYHZ. W, X, Y and Z represent different whole numbers. W = Z Y X Which row is correct when comparing the two hydrocarbons? empirical molecular relative formula formula molecular mass A different same different B different same same C same different different D same different same

1 marks

Answer: C

This question in 9701/12 Oct/Nov 2017

21 The diagram shows the skeletal formula of citric acid. O OH O O HO OH OH citric acid What is the molecular formula of citric acid? A C6H8O7 B C6H4O7 C C8H8O7 D C10H8O7

1 marks

Answer: A

This question in 9701/12 Oct/Nov 2017

1 Which formula represents the empirical formula of a compound? A C2H4O B C2H4O2 C C6H12 D H2O2

1 marks

Answer: A

This question in 9701/13 Oct/Nov 2017

16 Which fertiliser contains the greatest percentage of nitrogen by mass? A ammonium nitrate, NH4NO3 B ammonium sulfate, (NH4)2SO4 C diammonium hydrogen phosphate, (NH4)2HPO4 D urea, CO(NH2)2

1 marks

Answer: D

This question in 9701/13 Oct/Nov 2017

28 Ethanedioic acid has the formula HO2CCO2H. What is the formula of aluminium ethanedioate? A Al C2O4 B Al (C2O4)3 C Al 2C2O4 D Al 2(C2O4)3

1 marks

Answer: D

This question in 9701/12 Feb/March 2018

31 Compound Q contains 40% carbon by mass. What could Q be? 1 glucose, C6H12O6 2 starch, (C6H10O5)n 3 sucrose, C12H22O11

1 marks

Answer: D

This question in 9701/12 Feb/March 2018

40 The Mr of compound X is 72. The composition by mass of X is 66.7% carbon, 11.1% hydrogen and 22.2% oxygen. X gives an orange precipitate with 2,4-dinitrophenylhydrazine reagent. X does not react with Fehling’s reagent. What can be deduced from this information? 1 X is a carbonyl compound. 2 X is a ketone. 3 X is butanone.

1 marks

Answer: A

This question in 9701/11 May/June 2018

4 Compound J burns in excess oxygen to give carbon dioxide and water only. When a 3.00 g sample of compound J is burnt in excess oxygen, 4.40 g of carbon dioxide and 1.80 g of water are formed. What is the empirical formula of J? A CH B CHO C CH2 D CH2O

1 marks

Answer: D

This question in 9701/12 May/June 2018

31 Complete combustion of a sample of a hydrocarbon gave 0.132 g of carbon dioxide and 0.054 g of water. Which formulae could correctly represent this hydrocarbon? 1 CH2=CH2 2 CH3CH=CH2 3 CH3CH=CHCH3

1 marks

Answer: A

This question in 9701/13 May/June 2018

13 A solid Period 3 element, Q, is reacted with oxygen gas. Compound R is formed. When R is added to water the pH decreases. What could be the empirical formula of R? A Q2O4 B Q2O5 C Q4O10 D Q5O2

1 marks

Answer: B

This question in 9701/12 Feb/March 2019

18 Ammonium sulfate, (NH4)2SO4, and ammonium nitrate, NH4NO3, are used as fertilisers. These salts have different percentages by mass of nitrogen. They have the same effect as each other on the pH of wet neutral soil. Which row is correct? higher percentage effect on pH of soil of nitrogen by mass A ammonium nitrate decrease B ammonium nitrate increase C ammonium sulfate decrease D ammonium sulfate increase

1 marks

Answer: A

This question in 9701/12 May/June 2019

37 The diagram shows a compound used as a flame retardant. Br Br Br Br Br Br Which statements about this structure are correct? 1 The empirical formula is C2H3Br. 2 The C12 ring is not planar. 3 There are six chiral carbon atoms.

1 marks

Answer: A

This question in 9701/12 May/June 2019

21 The diagram shows the skeletal formula of compound Y. Y OH O O OH What is the empirical formula of Y? A CHO B CH2O2 C C2HO2 D C4H4O4

1 marks

Answer: A

This question in 9701/13 May/June 2019

25 Alcohol X is oxidised to form compound Y. The composition of Y is 54.54% carbon, 36.36% oxygen and 9.10% hydrogen. The Mr of Y is 88.0. What could be the structure of alcohol X? A CH3CH2CH(OH)CH3 B CH3CH2CH2CH2CH2OH C CH3CH2CH2CH2OH D CH3CH2CH(OH)CH2CH3

1 marks

Answer: C

This question in 9701/11 Oct/Nov 2019

21 The diagram shows the skeletal formula of phenazine. N N phenazine What is the empirical formula of phenazine? A C6H4N B C6H6N C C12H8N2 D C12H12N2

1 marks

Answer: A

This question in 9701/12 Oct/Nov 2019

25 Alcohol X is oxidised to form compound Y. The composition of Y is 54.54% carbon, 36.36% oxygen and 9.10% hydrogen. The Mr of Y is 88.0. What could be the structure of alcohol X? A CH3CH2CH(OH)CH3 B CH3CH2CH2CH2CH2OH C CH3CH2CH2CH2OH D CH3CH2CH(OH)CH2CH3

1 marks

Answer: C

This question in 9701/13 Oct/Nov 2019

2 For which hydrocarbon are the molecular and empirical formulae the same? A butane B ethane C pent-1-ene D propane

1 marks

Answer: D

This question in 9701/12 Feb/March 2020

3 Substance Q is a hydrocarbon. When 1.00 g of Q is completely burned, 3.22 g of carbon dioxide is produced. What could be the identity of Q? A cyclohexene B cyclopentane C ethene D pentane

1 marks

Answer: A

This question in 9701/12 Feb/March 2021

4 Originally, chemists thought indium oxide had the formula InO. By experiment they showed that 4.8 g of indium combined with 1.0 g of oxygen to produce 5.8 g of indium oxide. The Ar of oxygen was known to be 16. Which value for the Ar of indium is calculated using these data? A 38 B 77 C 115 D 154

1 marks

Answer: B

This question in 9701/12 Feb/March 2021

28 Ethanedioic acid has the formula HO2CCO2H. What is the formula of aluminium ethanedioate? A Al C2O4 B Al (C2O4)3 C Al 2C2O4 D Al 2(C2O4)3

1 marks

Answer: D

This question in 9701/12 Feb/March 2021

19 R is an oxide of Period 3 element T. 5.00 g of R contains 2.50 g of T. What is T? A magnesium B aluminium C silicon D sulfur

1 marks

Answer: D

This question in 9701/11 May/June 2021

32 Compound X is a straight chain hydrocarbon with an Mr of 84. What can be determined about X? 1 empirical formula 2 molecular formula 3 whether X contains a C=C bond or not

1 marks

Answer: A

This question in 9701/12 May/June 2021

1 Compound X is an organic compound that contains 30.6% carbon, 3.8% hydrogen, 20.4% oxygen and 45.2% chlorine by mass. What is the empirical formula of X? A C2H3OCl B C2H4OCl C C3H4OCl D C4H3O2Cl 2

1 marks

Answer: A

This question in 9701/13 May/June 2021

1 Compound X consists of 40.0% carbon, 6.7% hydrogen and 53.3% oxygen by mass. What is the empirical formula of compound X? A CH2O B C2H2O C C2H4O D CHO

1 marks

Answer: A

This question in 9701/12 Oct/Nov 2021

4 When a small sample of hydrocarbon Q is completely combusted, it produces 3.52 g of carbon dioxide and 1.44 g of water. What could be the structure of hydrocarbon Q? A B C D H C C C C H

1 marks

Answer: B

This question in 9701/12 May/June 2022

3 Analysis of the hormone thyroxine gives the results shown. Heating 0.500 g of thyroxine with aqueous silver nitrate produces 0.604 g of silver iodide. All of the iodine in the thyroxine sample is converted to silver iodide. Complete combustion of 0.500 g of thyroxine produces 232 cm3 of carbon dioxide and 7.72 cm3 of nitrogen, measured under room conditions. Which molecular formula of thyroxine agrees with these values? A C15H11NO4I4 Mr = 776.6 B C15H7NO4I8 Mr = 1280.2 C C30H25NO6I4 Mr = 1002.6 D C30H21NO6I8 Mr = 1506.2

1 marks

Answer: A

This question in 9701/13 May/June 2022

27 The diagram shows the skeletal formula of phenazine. phenazine N N What is the empirical formula of phenazine? A C6H4N B C6H6N C C12H8N2 D C12H12N2

1 marks

Answer: A

This question in 9701/13 May/June 2022

15 Hydrated cobalt(II) sulfate loses water when heated to give anhydrous cobalt(II) sulfate. All the water of crystallisation is lost to the atmosphere as steam. When 3.10 g of hydrated cobalt(II) sulfate, CoSO4•xH2O, is heated to constant mass the loss in mass is 1.39 g. What is the value of x, to the nearest whole number? A 4 B 6 C 7 D 11

1 marks

Answer: C

This question in 9701/12 Feb/March 2023

1 Sodium azide, NaN3 is an explosive used to inflate airbags in cars when they crash. It consists of positive sodium ions and negative azide ions. What are the numbers of electrons in the sodium ion and the azide ion? sodium ion azide ion A 10 20 B 10 22 C 12 20 D 12 22

1 marks

Answer: B

This question in 9701/11 Oct/Nov 2023

3 Aluminium carbide, Al 4C3, reacts readily with aqueous sodium hydroxide. The two products of the reaction are NaAlO2 and a hydrocarbon. Water molecules are also involved as reactants. What is the formula of the hydrocarbon? A CH4 B C2H6 C C3H8 D C6H12

1 marks

Answer: A

This question in 9701/11 Oct/Nov 2023

24 If ammonium cyanate is heated in the absence of air, the only product of the reaction is urea, CO(NH2)2. No other products are formed in the reaction. What is the formula of the cyanate ion present in ammonium cyanate? A CON2 – B CON2 2– C OCN – D OCN2–

1 marks

Answer: C

This question in 9701/11 Oct/Nov 2023

25 Hexamine is a crystalline solid used as a fuel in portable stoves. The diagram shows its skeletal structure. hexamine N N N N What is the empirical formula of hexamine? A CH2N B C3H6N2 C C4H8N4 D C6H12N4

1 marks

Answer: B

This question in 9701/11 Oct/Nov 2023

3 Aluminium carbide, Al 4C3, reacts readily with aqueous sodium hydroxide. The two products of the reaction are NaAlO2 and a hydrocarbon. Water molecules are also involved as reactants. What is the formula of the hydrocarbon? A CH4 B C2H6 C C3H8 D C6H12

1 marks

Answer: A

This question in 9701/13 Oct/Nov 2023

25 Hexamine is a crystalline solid used as a fuel in portable stoves. The diagram shows its skeletal structure. hexamine N N N N What is the empirical formula of hexamine? A CH2N B C3H6N2 C C4H8N4 D C6H12N4

1 marks

Answer: B

This question in 9701/13 Oct/Nov 2023

3 Which sodium compound contains 74.2% by mass of sodium? A sodium carbonate B sodium chloride C sodium hydroxide D sodium oxide

1 marks

Answer: D

This question in 9701/12 Feb/March 2024

1 Which pair of formulae is correct? A Ag2CO3 and (NH4)3NO3 B K2HCO3 and Zn3(PO4)2 C AgHCO3 and K3PO4 D ZnCO3 and (NH4)2PO4

1 marks

Answer: C

This question in 9701/12 May/June 2024

3 Glauber’s salt consists of crystals of hydrated sodium sulfate, Na2SO4•xH2O, which can be used for the manufacture of detergents. When a sample of Glauber’s salt was heated, 1.91 g of water was removed leaving 1.51 g of anhydrous Na2SO4. What is the value of x in Na2SO4•xH2O? A 1 B 8.85 C 10 D 11.25

1 marks

Answer: C

This question in 9701/11 Oct/Nov 2024

3 Glauber’s salt consists of crystals of hydrated sodium sulfate, Na2SO4•xH2O, which can be used for the manufacture of detergents. When a sample of Glauber’s salt was heated, 1.91 g of water was removed leaving 1.51 g of anhydrous Na2SO4. What is the value of x in Na2SO4•xH2O? A 1 B 8.85 C 10 D 11.25

1 marks

Answer: C

This question in 9701/13 Oct/Nov 2024

11 An experiment is carried out to determine the value of x in hydrated lithium hydroxide, LiOH•xH2O. A sample of the solid is heated in a crucible over a Bunsen flame. Complete dehydration takes place; decomposition does not occur. mass of empty crucible / g = Q mass of crucible with LiOH•xH2O / g = R mass of crucible and residue after heating / g = S Which equation gives the correct value of x? S – R R – S 23.9( R – S ) 23.9( S – R ) A B C D 18 18 18( S – Q ) 18( S – Q )

1 marks

Answer: C

This question in 9701/12 May/June 2025

15 The skeletal formulae of arginine and lysine are shown. arginine lysine NH O O H2N H2N N OH OH H NH2 NH2 Which row is correct? substance empirical formula Mr A arginine C3H7N2O 174 B arginine C3H8N2O 176 C lysine C3H7NO 144 D lysine C3H8NO 146

1 marks

Answer: A

This question in 9701/12 May/June 2025

2 What is the empirical formula of butanoic acid? A C2H4O B C3H6O C C4H8O D C5H10O

1 marks

Answer: A

This question in 9701/14 May/June 2025

20 Compound L has empirical formula NH. It decomposes on gentle heating to produce ammonia and compound M only. An aqueous solution of compound L is a good conductor of electricity. Which row could be correct? species present identity of M in L(aq) A N2H4 N3– and H+ B N2H4 NH4 + and NH2 – C HN3 NH3 and HN3 D HN3 NH4 + and N3 –

1 marks

Answer: D

This question in 9701/14 May/June 2025

3 What contains 9.03  1023 oxygen atoms? A 0.25mol aluminium oxide B 0.75mol sulfur dioxide C 1.5mol sulfur trioxide D 3.0mol water

1 marks

Answer: B

This question in 9701/11 Oct/Nov 2025

17 Three equations are listed. x, y and z are all whole numbers. 1 xAl + yO2zAl2O3 2 xMg + yO2zMgO 3 xNa + yO2zNa2O Which equations can be balanced if x = 4 and z = 2? A 1 and 3 B 1 only C 2 only D 3 only

1 marks

Answer: A

This question in 9701/11 Oct/Nov 2025

17 Three equations are listed. x, y and z are all whole numbers. 1 xAl + yO2zAl2O3 2 xMg + yO2zMgO 3 xNa + yO2zNa2O Which equations can be balanced if x = 4 and z = 2? A 1 and 3 B 1 only C 2 only D 3 only

1 marks

Answer: A

This question in 9701/13 Oct/Nov 2025