Question

Match List-I with List-II

List-ITests/Reagents/Observation(s)	List-IISpecies detected
(a) Lassaigne’s Test	(i) Carbon
(b) Cu (II) oxide	(ii) Sulphur
(c) Silver nitrate	(iii) N, S, P and halogen
(d) The sodium fusion extract gives black precipitate with acetic acid & lead acetate	(iv) Halogen specifically

a. (a)-(iii), (b)-(i),(c)-(iv), (d)-(ii)
b. (a)-(i), (b)-(iv),(c)-(iii), (d)-(ii)
c. (a)-(iii), (b)-(i),(c)-(ii), (d)-(iv)
d. (a)-(i), (b)-(ii),(c)-(iv), (d)-(iii)

Answer 1

Hint: In organic chemistry, there are many reagents which are useful in the detection of many species. For example, Lassaigne's test.

Complete Step by Step Solution:
Lassaigne's test helps in the detection of Sulphur, Nitrogen, and halogens present in any organic compounds. In this test, heating of a small-sized Na metal with the given organic compound is done inside a fusion tube. Due to this, the conversion of all elements into ionic form by Na takes place. Therefore, (a) matched with (iii)

The heating of an organic compound with Copper (II) oxide detects the Carbon. On strong heating, Carbon changes to Carbon dioxide. Therefore, (b) matched with (i).

The test of silver nitrate helps in the detection of halogens in an organic compound. In this test, precipitation of silver halides of different colours takes place in the end. The colour of silver halide is dependent on the halide ion of the compound. Therefore, (c) matched with (iv).

The sodium extract of any organic compound when acidified with acetic acid and added to a solution of lead acetate to it, a black precipitate formed. This means the compound contains Sulphur. Therefore, (d) matched with (ii).

Hence, option b, (a)-(i), (b)-(iv),(c)-(iii), (d)-(ii) is right answer.

Note: It is to be noted that Sodium metal is very reactive in nature. So, before using it in Lassaigne's test, it should be pressed using a filter paper to remove the kerosene oil.