Test for R.A. and O.A.

Which of the three unknown reagents is/are reducing agent(s)?

• F only

• F and H

• F and G

• G and H

An oxidising agent is added separately to aqueous potassium iodide and iron(II) sulfate. What colour changes will be observed in both solutions?

• A

• B

• C

• D

R is a solution containing an oxidising agent. It is added to each of the four reagents. Which is the correct observation?

• A

• B

• C

• D

From the results shown, which solutions may contain a reducing agent?

• 1 and 2 only

• 3 and 4 only

• 1 and 3 only

• 2 and 4 only

When bromine is added to aqueous alkali, the following reaction takes place.

Br₂(aq) + 2OH^-(aq) → Br^-(aq) + BrO^-(aq) + H₂O(l)

Which statement about this reaction is incorrect?

• Br₂ is reduced to Br^-

• Br₂ is oxidised to BrO^-

• OH^- is reduced to H₂O

• Oxidation and reduction occurs

In which reaction is the underlined substance acting as a reducing agent?

• 2NH₃(g) + H₂SO₄(aq) → (NH₄)₂SO₄(aq)

• 2C₂H₆(g) + 7O₂(g) → 4CO₂(g) + 6H₂O(g)

• Ag₂O(s) + H₂O₂(aq) → 2Ag(s) + H₂O(l) + O₂(g)

• MgCO₃(s) + 2HNO₃(aq) → Mg(NO₃)₂(aq) + H₂O(l) + CO₂(g)

Which reaction shows the greatest change in the oxidation state of sulfur?

• 2ZnS +3O₂ → 2ZnO + 2SO₂

• I₂ + 2S₂O₃²⁻ → 2I⁻ + S₄O₆²⁻

• H₂SO₄ + SO₃ → H₂S₂O₇

• S + O₂ → SO₂