9701/21

Chemistry 9701/21May/June 2021

Cambridge AS Level · AS Level Structured Questions · worked solutions for every part, with the mark scheme

6
questions
60
marks
75
minutes

Topics Atoms, Molecules and Stoichiometry · Electrochemistry · Chemical Bonding · Group 17 · Hydrocarbons · Group 2 · +6 more

Q1Atoms, Molecules and StoichiometryElectrochemistryGroup 2Free sample

Ethanedioic acid, HO₂CCO₂H, has a relative molecular mass of 90.0.

(a)
(i)

Explain what is meant by the term relative molecular mass.

2M
(ii)

State the empirical formula of ethanedioic acid.

1M
(iii)

Calculate how many atoms of carbon are present in 0.18g of ethanedioic acid, HO₂CCO₂H.

Show your working.

3M
(b)

Solid ethanedioic acid reacts with aqueous calcium ions to make a precipitate of calcium ethanedioate, CaC₂O₄.

CaC₂O₄ breaks down when heated to form calcium oxide, carbon dioxide and carbon monoxide.

(i)

Construct an equation to represent the reaction of CaC₂O₄ when heated. Include state symbols.

2M
(ii)

Identify the type of reaction which occurs when CaC₂O₄ is heated.

1M
(iii)

Identify another compound containing calcium ions which will also produce carbon dioxide and calcium oxide when it is heated.

1M

The rest of this paper

5 more questions
  • Q2Chemical Bonding · States of Matter11M
  • Q3Group 17 · Atoms, Molecules and Stoichiometry · Electrochemistry8M
  • Q4Electrochemistry · Group 17 · Reaction Kinetics · Chemical Bonding9M
  • Q5Introduction to Organic Chemistry · Hydrocarbons · Atoms, Molecules and Stoichiometry · Carboxylic Acids and Derivatives · Polymerisation10M
  • Q6Hydrocarbons · Chemical Bonding · Halogen Compounds12M
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