Question
A capillary tube is dipped in water. The water rises to certain height. What will happen if we add some common salt in water?
Solution
On adding highly insoluble impurities in water, the surface tension decreases. And, also the height to which the liquid rises into the capillary tube is directly proportional to the surface tension of the liquid. As salt is added in water, surface tension of water increases. Therefore, the height to which the water rises in the capillary tube increases on adding the salt.
