Chemistry 0620 · IGCSE · Preparation of salts

Preparation of salts — practice question

Sulfur is a significant element.
(a)[2]

Explain how the burning of fossil fuels that contain sulfur results in acid rain.

(b(i))[2]

Write a chemical equation for this reversible reaction. Make sure you include the correct symbol to show that the reaction is reversible.

(b(ii))[3]

State the conditions and give the catalyst used for this reversible reaction. temperature pressure catalyst

(b(iii))[2]

Describe how the sulfur trioxide made is changed into sulfuric acid in the following stages of the Contact process.

(c(i))[1]

State a suitable apparatus for measuring 20 cm$^3$ of dilute sulfuric acid in step 1.

(c(ii))[2]

State two observations that would show step 1 has finished.

(c(iii))[1]

Why must an excess of zinc carbonate be added in step 1?

(c(iv))[2]

What does the term saturated solution mean in step 3?

(c(v))[1]

Finish the equation by adding the correct state symbol for zinc sulfate.

(c(vi))[1]

Name one more zinc compound that could be used to make zinc sulfate from dilute sulfuric acid by this method.

(c(vii))[1]

Suggest why this method would fail to make barium sulfate from barium carbonate and dilute sulfuric acid.

(d(i))[1]

What colour was the methyl orange in the aqueous sodium hydroxide?

(d(ii))[4]

Determine the concentration of the dilute sulfuric acid in g/dm$^3$. Work out the number of moles of aqueous sodium hydroxide placed in the conical flask. Work out the number of moles of dilute sulfuric acid delivered from the burette. Work out the concentration of the dilute sulfuric acid in mol/dm$^3$. Work out the concentration of the dilute sulfuric acid in g/dm$^3$.

(e)[3]

Calculate the percentage yield obtained in this reaction.

Worked solution & mark scheme

This 26-mark question has a full step-by-step worked solution and mark scheme. One marking point: Sulfur dioxide / SO₂ is produced

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