You visited us 1 times! Enjoying our articles? Unlock Full Access!

Oxides of Sulphur

A green color...

Question

A green colored water soluble substance, $(A)$ , forms a greenish precipitate $(B)$ with $N H_{4} O H$ in presence of $N H_{4} C l$ (excess). When $(B)$ is oxidized with a little sodium bismuthate in presence of $H_{2} S O_{4}$ , a orange solution is obtained. If now a little solid $N a_{2} O_{2}$ is added, an intensely blue-colored compound is formed, extractable with ether. $(A)$ yields a bulky white precipitate with $B a C l_{2}$ solution. Suggest the nature of the compound $(A)$ :

Nickel (II) sulphate

No worries! We‘ve got your back. Try BYJU‘S free classes today!

Copper (II) sulphate

No worries! We‘ve got your back. Try BYJU‘S free classes today!

Chromium (III) sulphate

Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses

Ferrous sulphate

No worries! We‘ve got your back. Try BYJU‘S free classes today!

Open in App

Solution

The correct option is C Chromium (III) sulphate
Compound (A) is chromium (III) sulphate $C r_{2} (S O_{4})_{3}$ .
It is green coloured and water soluble. In presence of excess $N H_{4} C l$ , it reacts with $N H_{4} O H$ to form green precipitate of chromium (III) hydroxide $C r (O H)_{3}$
When chromium (III) hydroxide is oxidized with a little sodium bismuthate in presence of $H_{2} S O_{4}$ , a orange solution is obtained. If now a little solid $N a_{2} O_{2}$ is added, an intensely blue-colored compound is formed, extractable with ether.
Chromium (III) sulphate yields a bulky white precipitate of barium sulphate $B a S O_{4}$ with $B a C l_{2}$ solution.
$C r_{2} (S O_{4})_{3} + 3 B a C l_{2} \to 3 B a S O_{4} + 2 C r C l_{3}$

Suggest Corrections

Similar questions

A black colored compound (A) on reaction with dilute

H_{2} S O_{4}

gives a gas (B) which on passing in a solution of acid (C) gives white turbidity (D). Gas (B) when placed in an acidified solution of a compound (E) gives a precipitate (F) soluble in dilute

H N O_{3} .

After boiling this solution, when an excess of

N H_{4} O H

is added, blue colored compound (G) is formed. To this solution on addition of

C H_{3} C O O H

and aqueous

K_{4} [F e (C N)_{6}]

, a chocolate precipitate (H) is obtained. On the addition of an aqueous solution of

B a C l_{2}

to an aqueous solution of E, a white ppt insoluble in

H N O_{3}

is obtained.

Identify B.

A black colored compound (A) on reaction with

d i l . H_{2} S O_{4}

gives a gas (B) which on passing in a solution of acid (C) gives white turbidity (D). Gas (B) when passed in an acidified solution of a compound (E) gives a black precipitate (F) which is soluble in hot concentrated (C). After boiling this solution when an excess of ammonia solution is added, a blue-colored compound (G) is formed. To the solution of (E), on the addition of acetic acid and aqueous potassium ferrocyanide, a chocolate brown precipitate (H) is formed. On the addition of an aqueous solution of

B a C l_{2}

to an aqueous solution of (E), white precipitate insoluble in

H N O_{3}

is obtained.

The gas (B) on passing through an acid (C) gives white turbidity (D) because :

A black colored (insoluble in

H_{2} O

) solid A does not dissolve in

H N O_{3}

. Aqua regia can dissolve A forming B. B gives yellow precipitate C with

N a O H

. B also gives an orange ppt. D with

K I

. D dissolves in excess of

K I

forming E. E gives brown ppt. with

N H_{4}^{+}

salt in presence of

N a O H

. A is precipitated if

H_{2} S

gas is passed into the solution of B in

d i l . H C l

The compound C is :

Q. The white solid compound A decomposes quite rapidly on heating in the presence of a black substance X to form a solid compound B and a gas C. When an aqueous solution of compound B is reacted with silver nitrate solution, then a white precipitate of silver chloride is obtained along with potassium nitrate solution. Gas C does not burn itself but helps to burn other things.
What is compound B?

A colorless solid (A) when placed into water produces a heavy white turbidity to (B). Solid (A) gives a clear solution in

c o n c . H C l

when

H C l

solution is added to large amounts of water, (B) forms again. (B) dissolves in dilute HCl. When

H_{2} S

is passed through a suspension of (A) or (B); a black precipitate (C) forms, (C) is insoluble in yellow ammonium sulphide

(N H_{4})_{2} S

C o n c . H_{2} S O_{4}

added to solid (A) liberates gas (D). Gas(D) is water-soluble and gives white precipitate with mercuric salts (E) and not mercuric salts. The black precipitate (C) dissolves in

H N O_{3}

(1:1) to give a solution to which

H_{2} S O_{4}

is added followed by addition of

N H_{4} O H

when a white precipitate (F) is formed. (E) gives a black ppt. (G) with solution of sodium stannite.

When compound (A) reacts with

N H_{4} O H

, then product is a:

Join BYJU'S Learning Program