Question

16. Explain the following observations:

i. Water wets glass surface but does not wet the waxed glass surface.
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Answer 1

the adhesive forces between the drops are stronger than cohesive force between the liquid

Answer 2

because the cohesive forces within the drops are stronger than the adhesive forces between the drops and the wax. Water wets glass and spreads out on it because the adhesive forces between the liquid and the glass are stronger than the cohesive forces within the water.