Chemistry 9701/21 — May/June 2019

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

questions

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Topics Chemical Bonding · Atoms, Molecules and Stoichiometry · States of Matter · Introduction to Organic Chemistry · Carbonyl Compounds · Group 2 · +7 more

Q1Group 2Free sample

(a)

Group 2 elements share common chemical properties.

(i)

Calcium reacts in cold water more quickly than magnesium because more energy is required to remove the outer electrons in magnesium. This occurs even though calcium atoms have a greater nuclear charge.

Explain why more energy is required to remove the outer electrons in magnesium than in calcium.

(ii)

$0.001\text{ mol}$ of strontium reacts with an excess of cold water. When the reaction is complete a colourless solution is seen.

Construct the equation for the reaction of strontium with cold water. Include state symbols.

(iii)

$0.005\text{ mol}$ of calcium and $0.005\text{ mol}$ of strontium are added separately to two beakers. Each beaker contains $100\text{ cm}^3$ of cold water.
At the end of each reaction a white solid and a colourless solution are seen in both beakers.

Predict which element, calcium or strontium, produces the more alkaline solution. Explain your answer.

(iv)

Describe one observation when magnesium carbonate is added to excess dilute sulfuric acid.

(b)

Element $\text{X}$ is a metal. $\text{X}$ reacts with oxygen to form a black solid oxide. The oxidation state of $\text{X}$ in this oxide is $+2$ . The carbonate of $\text{X}$ , $\text{XCO}_3$ , is a green solid. It decomposes on heating to form the oxide and a colourless gas.

(i)

From the information given, state two similarities and one difference that metal $\text{X}$ and its compounds have with Group 2 metals and their compounds.

similarity 1

similarity 2

difference 1

(ii)

Write the formula of the oxide of $\text{X}$ .

(iii)

Write an equation for the reaction of $\text{XCO}_3$ when it is heated.

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4 more questions

Q2Chemical Bonding · Atoms, Molecules and Stoichiometry · States of Matter · Reaction Kinetics · Group IV (Group 14)15M
Q3Atomic Structure · States of Matter · Atoms, Molecules and Stoichiometry11M
Q4Introduction to Organic Chemistry · Chemical Bonding · Hydrocarbons · Hydroxy Compounds · Carbonyl Compounds15M
Q5Introduction to Organic Chemistry · Carbonyl Compounds · Carboxylic Acids and Derivatives · Nitrogen Compounds7M

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