Question

Assertion: The impurities always decrease the surface tension of a liquid. 

Reason: The change in surface tension of the liquid depends upon the degree of contamination of the impurity.

(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. 

Answer 1

Correct option: (e)

Explanation:

The presence of impurities either on the liquid surface or dissolved in it, affect surface tension depending upon degree of contamination. A highly soluble substance when dissolved in water increases surface tension & substance like phenol, reduces surface tension of water. 

Hence assertion is wrong & reason is true.