Question

1. (5) Solid nickel reacts with aqueous nitric acid (HNO3) to form aqueous nickel (III) nitrate and

hydrogen gas. Write out and balance the chemical equation, including phases.
2. (5) What type of reaction is this? Can it undergo redox? If so, write out the balanced half-
reactions

Answer 1

See every answer with its explanation below

Step-by-step explanation:

1. Write the molecular equation

• Ni(s) + HNO₃ (aq) → Ni(NO₃)₃ (aq) + H₂(g)

↑ ↑ ↑ ↑

solid nickel aqueous nitric aqueous nickel(III) hydrogen gas

acid nitrate

2. Balance the molecular equation:

• 2Ni(s) + 6HNO₃ (aq) → 2 Ni(NO₃)₃ (aq) + 3H₂(g)

3. Type of reaction

This is a replacement reaction because the nickle is taking the place of hydrogen in the nitric acid and the hydrogen is released. It is also a redox reaction because nickel is being oxidized and hydrogen is being reduced.

The balanced half-reactions are:

• Oxidation reaction:

2Ni⁰ → 2Ni³⁺ + 2×(3e⁻)

Each nickle atom loses 3 electrons increasing its oxidation state from 0 to +3.

• Reduction reaction:

6H⁺ + 6e⁻ → 3H₂⁰

Each H⁺ gains 1 electron reducing its oxidation state from +1 to 0.