Question

Surface tension does not vary with the presence of impurities.

• A. True
• B. False

Answer 1

The correct option is B False

Is this very tough?
We only discussed temperature mainly. But, will it vary with the presence of impurities?
We have already discussed the definition of surface tension.
Now let's discuss the effect of presence of impurities on surface tension.
Impurities affect surface tension appreciably. It is observed that impurities, which tend to concentrate on the surface of liquids, compared to its bulk lower the surface tension. Substances like detergents, soaps, alcohol lower the surface tension of water, while inorganic impurities present in the bulk of a liquid such as NaCl tend to increase the surface tension of water.