Inorganic chemistry: Groups 1, 2 and 7Edexcel A-Level Chemistry: Topic test

20 questions, 54 marks

Edexcel A-Level Chemistry

Inorganic chemistry: Groups 1, 2 and 7 topic test

Total 54 marks

Name

Class

Date

1
Barium sulfate is swallowed as a 'barium meal' so that the digestive system shows up on X-ray images. Soluble barium compounds are toxic.
(a)
Which Group 2 sulfate is the least soluble in water?
[1 mark]
AMagnesium sulfate
BCalcium sulfate
CStrontium sulfate
DBarium sulfate
(b)
Which reagent is used to test for sulfate ions in solution?
[1 mark]
ASilver nitrate solution, then dilute ammonia
BAcidified barium chloride solution
CDilute hydrochloric acid
DSodium hydroxide solution, warmed
(c)
Barium carbonate is also insoluble in water but must never be used as a barium meal. Explain why, using an ionic equation.
[2 marks]
Total for question 1: 4 marks
2
Magnesium burns in oxygen with a bright white flame. Calcium reacts steadily with cold water and barium reacts vigorously with cold water.
(a)
Which is the balanced equation for the reaction of calcium with cold water?
[1 mark]
ACa + H₂O → CaO + H₂
BCa + H₂O → Ca(OH)₂ + H₂
CCa + 2H₂O → Ca(OH)₂ + H₂
D2Ca + 2H₂O → 2CaOH + H₂
(b)
Which statement explains why barium is more reactive than calcium?
[1 mark]
ABarium atoms lose their outer electrons more easily because the outer electrons are further from the nucleus and more shielded
BBarium has a higher nuclear charge, which attracts electrons more strongly
CBarium atoms have more electrons in the outer shell
DBarium has a higher first ionisation energy
(c)
Write an equation for the reaction of magnesium with oxygen. State the change in the oxidation number of magnesium.
[2 marks]
Total for question 2: 4 marks
3
Hydrogen chloride and hydrogen iodide are colourless gases that dissolve in water to form strongly acidic solutions. Hydrogen chloride also reacts with ammonia gas.
(a)
Write an equation, including state symbols, for the reaction of hydrogen chloride gas with water. Write an equation, including state symbols, for the reaction of hydrogen chloride gas with ammonia gas and state what is seen.
[3 marks]
(b)
Hydrogen iodide is a much stronger reducing agent than hydrogen chloride. Explain this difference in terms of the halide ions, and write the half-equation for the oxidation of iodide ions.
[4 marks]
Total for question 3: 7 marks
4
Fluorine is the first and astatine is the last element in Group 7. Fluorine, F₂, is a pale yellow gas. Astatine is radioactive and extremely rare, so its properties are predicted from the trends in the group.
(a)
Predict the physical state of astatine at room temperature and its electronegativity compared with iodine, giving reasons. Explain why fluorine is the most reactive halogen, and predict whether fluorine would oxidise chloride ions and whether astatine would oxidise iodide ions.
[6 marks]
(b)
Predict what would be seen when aqueous silver nitrate is added to aqueous sodium fluoride and to aqueous sodium astatide. Explain why astatide ions are expected to be the strongest reducing agent of the halide ions, and predict the products when solid sodium astatide is warmed with concentrated sulfuric acid.
[6 marks]
Total for question 4: 12 marks
5
Limestone, calcium carbonate, is heated in a kiln at about 1000 °C to make quicklime, calcium oxide.
(a)
Which carbonate does not decompose when it is heated strongly in a Bunsen burner flame?
[1 mark]
ALi₂CO₃
BNa₂CO₃
CMgCO₃
DCaCO₃
(b)
Which is the ionic equation for the reaction of solid calcium carbonate with dilute hydrochloric acid?
[1 mark]
ACO₃²⁻ + H⁺ → CO₂ + H₂O
BCO₃²⁻ + 2H⁺ → CO₂ + H₂O
CCaCO₃ + 2HCl → CaCl₂ + CO₂ + H₂O
DCaCO₃ + 2H⁺ → Ca²⁺ + CO₂ + H₂O
(c)
Barium carbonate decomposes at a higher temperature than calcium carbonate. Explain why.
[2 marks]
Total for question 5: 4 marks
6
Fireworks contain metal compounds that colour the flame. Strontium compounds give a red flame.
(a)
What causes the coloured light that is seen in a flame test?
[1 mark]
AMetal atoms lose electrons to form positive ions
BMetal ions are reduced in the flame
CElectrons are excited to higher energy levels and then fall back, releasing light of specific frequencies
DThe compound decomposes to release coloured gases
(b)
Which metal ion gives a lilac flame?
[1 mark]
AK⁺
BNa⁺
CCa²⁺
DBa²⁺
(c)
Explain why compounds of different metals give flames of different colours.
[2 marks]
Total for question 6: 4 marks
7
A sample of rock salt (impure sodium chloride) from a mine is thought to contain sodium carbonate and sodium sulfate as impurities.
(a)
Explain why the solution of the rock salt is acidified with dilute nitric acid before aqueous silver nitrate is added to test for chloride ions.
[3 marks]
(b)
Describe how to test separate portions of a solution of the rock salt for sulfate ions and for chloride ions. Give the result of each positive test and an ionic equation for the sulfate test.
[4 marks]
Total for question 7: 7 marks
8
Bromine is manufactured from sea water that contains bromide ions. Chlorine gas is bubbled through acidified sea water, and the bromine formed is blown out with a stream of air. The bromine is then absorbed in cold aqueous sodium hydroxide, and the resulting solution is later acidified to release bromine again.
(a)
Explain why chlorine can be used to release bromine from the sea water, in terms of oxidation numbers and the trend in reactivity down Group 7. Include the ionic equation for the reaction.
[6 marks]
(b)
Bromine reacts with cold aqueous sodium hydroxide to form sodium bromide, sodium bromate(I), NaBrO, and water. Write the ionic equation for the reaction and use oxidation numbers to explain why it is disproportionation. Explain, using oxidation numbers, why bromine is released when the resulting solution is acidified.
[6 marks]
Total for question 8: 12 marks

End of questions

Written by the Exaim team, led by Shaun Daswani (Head of Upper Secondary, Improve ME Institute; MSc Financial Mathematics, Imperial College London; BSc, UCL) and Jason Daswani (operational lead, Improve ME Institute; LSE).