Question

41.
Identify A in the following reaction.
A + (NH4)2SO4
+
2NH4OH (excess)
Colourless
Solution​

Answer 1

Answer:

EXERCISE- 1 (A)

Question 1:

Write the probable colour of the following salts.

(a) Ferrous salts

(b) Ammonium salts

(c) Cupric salts

(d) Calcium salts

(e) Aluminium Salts

Solution 1:

(a) Ferrous salts : Light green

(b) Ammonium salts : Colourless

(c) Cupric salts : Blue

(d) Calcium salts : Colourless

(e) Aluminium salts : Colourless

Question 2:

Name:

(a) a metallic hydroxide soluble in excess of NH4OH.

(b) a metallic oxide solube in excess of caustic soda solution.

(c) a strong alkali

(d) a weak alkali

(e) two coloured metal ions

(f) two coloured metal ions

(g) a metal that evolves a gas which burns with a pop sound when boiled with alkali solutions.

(h) two bases which are not alkalis but dissolves in alkalis to yield colourless solutions.

(j) a coloured cation not a representative element.

Solution 2:

(a) Cu(OH)2

(b) ZnO

(c) NaOH

(d) NH4OH

(e) Na+

, Ca2+

(f) Fe2+, Mn2+

(g) Aluminium

Answer 2

A is the "Zinc hydroxide" - $Zn(OH)_{2}$ in the given reaction.

Explanation:

1. The following is the balanced chemical equation obtained by the reaction of copper hydroxide with ammonium sulphate.

$Zn(OH)_{2} + (NH_{4} )_{2} SO_{4} + 2NH_{4} OH$(excess) → $[Zn(NH_{3} )_{4} ]SO_{4} + 4H_{2} O$(colourless solution).

⇒The product obtained is the colourless solution which is called "Tetramminezinc(II) Sulphate".