Question

Please finish the molecular equations.

Zn (s) + CuCl2 (aq)

Zn (s) + HCl (aq)

Also what kind of reaction occurs (single displacement, exchange, combustion, combination, decomposition) when:

NaOH is added to Cu(NO3)2

Cupric hydroxide is added to Cuprix oxide

Cupric oxide to cupric chloride

cupric chloride to copper

Answer 1

Molecular Equations & Reaction Types :-

1. Zn (s) + CuCl₂ (aq) →

• Reaction: Single displacement

• Equation:

  $$\text{Zn (s)}+{\text{CuCl}}_2\text{(aq)}\to {\text{ZnCl}}_2\text{(aq)}+\text{Cu (s)}$$

  (Zinc displaces copper because Zn is more reactive.)

2. Zn (s) + HCl (aq) →

• Reaction: Single displacement

• Equation:

  $$\text{Zn (s)}+2\text{HCl (aq)}\to {\text{ZnCl}}_2\text{(aq)}+{\text{H}}_2\text{(g)}$$

  (Zinc displaces hydrogen, producing H₂ gas.)

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Reaction Types :-

1. NaOH + Cu(NO₃)₂ →

• Type: Double displacement (exchange)

• Equation:

  $$2\text{NaOH}+{\text{Cu(NO₃)}}_2\to {\text{Cu(OH)}}_2\text{(s)}+2{\text{NaNO}}_3\text{(aq)}$$

2. Cu(OH)₂ → CuO :

• Type: Decomposition

• Equation:

  $${\text{Cu(OH)}}_2\to \text{CuO}+{\text{H}}_2\text{O}$$

3. CuO → CuCl₂ :

• Type: Combination (with HCl)

• Equation:

  $$\text{CuO}+2\text{HCl}\to {\text{CuCl}}_2+{\text{H}}_2\text{O}$$

4. CuCl₂ → Cu :

• Type: Single displacement (e.g., with Zn or Fe)

• Equation:

  $${\text{CuCl}}_2+\text{Zn}\to {\text{ZnCl}}_2+\text{Cu}$$

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Summary :-

• Single displacement: Zn reactions, CuCl₂ → Cu.

• Double displacement: NaOH + Cu(NO₃)₂.

• Decomposition: Cu(OH)₂ → CuO.

• Combination: CuO → CuCl₂.