Question

What is the effect of temperature on (i) vapour pressure (ii) surface tension and (iii) viscosity of a liquid?

Answer 1

Answer:1) surface tension decreases with increase in temperature. And vice versa

2) vapour pressure increases with increase in temperature.

3) viscosity decreases with increase in temperature

Explanation: the former effect causes a decrease in the shear stress while the latter causes it to increase. With high temperatures, viscosity in gases increases while in liquids decreases.

Surface tension decreases as cohesive forces decreases with an increase of molecular thermal activity ( lowering of intermolecular forces).

Answer 2

It has no component perpendicular to the horizontal surface. As a result, there is no pressure difference between the liquid side and the vapour side. ... Thus, there is always an excess of pressure on the concave side of a curved liquid surface over the pressure on its convex side due to surface tension.