MyQuestionIcon

2

You visited us 2 times! Enjoying our articles? Unlock Full Access!

Methods to Form Lyophobic Colloids

A freshly pre...

Question

A freshly prepared saturated solution of a potassium salt produces a yellow precipitate with a highly concentrated solution of cobalt (II) chlorine when acetic acid is added to it.
The potassium salt may be :

A

K N O_{2}

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

B

K_{2} S O_{3}

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

C

K N O_{3}

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

D

K B r

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

Open in App

Solution

The correct option is A $K N O_{2}$
Cobalt precipitates in sulphide form. When cobalt sulphide is treated with aqua regia and then with strong solution of potassium nitrite in the presence of acetic acid, a yellow precipitate of potassium hexanitritocobaltate (III) ( $K_{3} [C o (N O_{2})_{6}]$ ) complex is formed.
The reactions are as follows:
$C o S + H N O_{3} + 3 H C l \to C o C l_{2} + N O C l + S + 2 H_{2} O$
$C o C l_{2} + 7 K N O_{2} + 2 C H_{3} C O O H \to K_{3} [C o (N O_{2})_{6}] ↓ (yellow ppt.)$
$+ N O + H_{2} O + 2 K C l + 2 C H_{3} C O O K$

Suggest Corrections

thumbs-up

0

Similar questions

Q. A metal salt solution forms a yellow precipitate with potassium chromate in acetic acid, a white precipitate with dilute sulphuric acid, but gives no precipitate with sodium chloride or iodide. The white precipitate obtained when sodium carbonate is added to the metal salt solution consists of:

Q. For preparing an alkane a concentrated aqueous solution of sodium or potassium salt of a saturated carboxylic acid is subjected to:

Q. Salts A, B, C, D and E undergo reactions (i) to (v) respectively. Identify the anion present in these salts on the basis of these reactions. Tabulate your answers in the format given below:
(i) When silver nitrate solution is added to a solution of A, a white precipitate, insoluble in dilute nitric acid, is formed.
(ii) Addition of dilute hydrochloric acid to B produces a gas which turns lead acetate paper black.
(iii) When a freshly prepared solution of ferrous sulphate is added to a solution of C and concentrated sulphuric acid is gently poured from the side of the test tube, a brown ring is formed.
(iv) When dilute sulphuric acid is added to D, a gas is produced which turns acidified potassium dichromate solution from orange to green.
(v) Addition of dilute hydrochloric acid to E produces an effervescence. The gas produced turns limewater milky but does not affect acidified potassium dichromate solution.

Salt	Anion
A
B
C
D
E

In the preparation of alkanes; a concentrated aqueous solution of sodium or potassium salts of saturated carboxylic acid are subjected to

Q. The colour of the precipitate formed when Cobalt (

I I

) solution reacts with

K {N O}_{2}

in acetic acid medium is:

View More

Join BYJU'S Learning Program

similar_icon

Related Videos

lock

Methods to Form Lyophobic Colloids

CHEMISTRY

Watch in App

explore_more_icon

Explore more

Methods to Form Lyophobic Colloids

Standard XII Chemistry

Join BYJU'S Learning Program

CrossIcon