2. Assertion : It is better to wash the clothes in cold soap solution. Reason : The surface tension of cold solution is more than the surface tension of hot solution.

Read the assertion and reason carefully to mark the correct option out of the options given below:

(a)       If both assertion and reason are true and the reason is the correct explanation of the assertion.

(b)       If both assertion and reason are true but reason is not the correct explanation of the assertion.

(c)        If assertion is true but reason is false.

(d)       If the assertion and reason both are false.

(e)       If assertion is false but reason is true.

Ans. (e)   The soap solution, has less surface tension as compared to ordinary water and its surface tension decreases further on heating. The hot soap solution can, therefore spread over large surface area and also it has more wetting power. It is on account of this property that hot soap solution can penetrate and clean the clothes better than the ordinary water.

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