Question

define surface tension explain the effect of impurity of surface tension ​

Answer 1

Answer:

(i) The angle of contact or the surface tension of liquid increases with dissolved impurities like common salt. For dissolved impurities, the angle of contact (or surface tension) increases linearly with the concentration of the dissolved materials.

(iii) It decreases with sparingly soluble substances like phenol or alcohol. A detergent is a surfactant whose molecules have hydrophobic and hydrophilic ends; the hydrophobic ends decrease the surtace tension of water. With reduced surface tension, the water can penetrate deep into the fibres of a cloth and remove stubborn stains.

(iii) It decreases with insoluble surface impurities like oil, grease or dust. For example, nmercury surface contaminated with dust does not form pertect Spherical droplets till the dust is removed.