Question

state the relevant observation for each of the following sodium hydroxide is slowly added and than in excess, tio zinc sulphate solution​

Answer 1

Answer:

ANSWER

When sodium hydroxide solution is added drop by drop to zinc sulphate solution a white precipitate is formed which is soluble in excess of sodium hydroxide.

ZnSO

4

+2NaOH→Zn(OH)

2

+Na

2

SO

4

Zn(OH)

2

+2NaOH→Na

2

ZnO

2

+2H

2

O

Answer 2

Sodium hydroxide solution is slowly added and then in excess to zinc sulphate solution.

• Sodium hydroxide solution when slowly added to zinc sulphate solution, a white precipitate of zinc hydroxide is obtained, which is soluble in excess of sodium hydroxideto form a clear solution of sodium zincate.

• ZnSO4 + 2NaOH → Zn(OH)2 ↓ + Na2SO4

where, Zn(OH)2 is a white precipitate obtained.

• Since, NaOH is in excess it reacts again with Zn(OH)2 to form sodium zincate.

Zn(OH)2 + 2NaOH → Na2ZnO2 ↓ + 2H2O