Question

A student, by mistake, mixed sulphur powder with iron filings. The following techniques were suggested to separate the sulphur from the mixture out of which he has to choose one :
A. dissolving in carbon disulphide, filtration, evaporation
B. dissolving in water at room temperature and filtration
C. dissolving in hot water, filtration and evaporation
D. dissolving in ice cold water and filtration
The correct technique is :
(1) A
(2) B
(3) C
(4) D

Answer 1

Addition of carbon disulphide to a mixture containing iron filings and sulphur powder leads to the formation of a clear yellow solution when sulphur powder dissolves in carbon disulphide, on gentle shaking. Iron fillings being insoluble settle in the bottom. These can be separated by filtration. When the solution is allowed to evaporate, the powder of solid sulphur is obtained.

Hence, the correct answer is option 1.