Question

Winnowing is used only for :
A.homogeneous solid - solid mixtures
B.homogeneous solid - liquid mixtures
C.heterogeneous solid - liquid mixtures
D.heterogeneous solid - solid mixtures

Answer 1

Winnowing is a method of separation which is used to separate individual components from a mixture. The method of separation is decided on the basis of the nature of components to be separated.

Complete step by step answer:
Mixtures are of basically of two types :
A mixture in which the constituents are uniformly distributed throughout without any clear boundary of separation is called homogeneous mixture .
A mixture that does not have uniform composition, that is it has visible boundaries of separation between its constituents, is called heterogeneous mixture .
The grain which is harvested from the field consists of various impurities , winnowing is a method to separate grain from lighter particles such as chaff or dirt .
As we know that grain and chaff both are solid in nature therefore it is a solid - solid mixture .
Since the constituents are not distributed uniformly therefore it is a heterogeneous mixture and can be separated by simple physical method

So, the correct answer is Option D.

Note:
The selection of methods to separate the components of a mixture depends upon the nature of the components present in the mixture . Homogeneous mixtures require special methods to separate its constituents whereas heterogeneous mixtures can be separated into their constituents by simple physical methods .