Question

Classify each of the following reactions as combination, decomposition, displacement or double displacement reactions:(a) Zn (s) + 2AgNO3 (aq) ⎯⎯→ Zn(NO3)2 + 2Ag (s)(b) 2KNO3 (s) heat ⎯⎯⎯→ 2KNO2 + O2 (g)(c) Ni (NO3)2 (aq) + 2NaOH (aq) ⎯⎯→ Ni(OH)2 (s) + 2NaNO3 (aq)(d) 2KClO3 (s) heat ⎯⎯⎯→ 2KCl (s) + 3O2 (g)(e) MgO (s) + C (s) ⎯⎯→ CO (g) + Mg (s)

Answer 1

Explanation:

1-displacement

2-decomposition

3-double displacement

4-decomposition

5-double displacement

Answer 2

Answer:

(a) Zn (s) + 2AgNO3 (aq) ⎯⎯→ Zn(NO3)2 + 2Ag (s)

Displacement reaction.

(b) 2KNO3 (s) heat ⎯⎯⎯→ 2KNO2 + O2 (g)

Decomposition reaction.

(c) Ni (NO3)2 (aq) + 2NaOH (aq) ⎯⎯→ Ni(OH)2 (s) + 2NaNO3 (aq)

Double displacement reaction

(d) 2KClO3 (s) heat ⎯⎯⎯→ 2KCl (s) + 3O2 (g)

Decomposition reaction.

(e) MgO (s) + C (s) ⎯⎯→ CO (g) + Mg (s)

Displacement reaction.

Explanation:

In a combination reaction, two or more elements or compounds combine to form a single compound.

Equation: X + Y → XY.

In a decomposition reaction, one compound decomposes to give two elements or compounds.

Equation: XY → X + Y

In a displacement reaction, one element replaces another element from a compound.

Equation: XY + Z → XZ + Y.

In a double displacement reaction, one element from one compound replaces another element from the other compound.

Equation: AB + CD → AD + CB.