Question

As we increase the temperature of a liquid, its properties change. Which of the following would NOT be an expected change in the properties of a liquid as we increase its temperature?a. decrease in viscosity b. decrease in density c. increase in surface tension d. increase in vapor pressure e. increase in tendency to evaporate

Answer 1

Answer: c. increase in surface tension

Explanation:

a) Viscosity : is defined as the resistance to the flow of a fluid. More are the inter molecular forces between the particles of a liquid, the more the viscosity of the liquid and thus it will flow slowly.

Viscosity decreases with increase in temperature as the forces among particles decrease due to increase in kinetic energy and thus they offer less resistance to flow.

c) Surface tension : is the downward force acting on the surface of liquid due to presence of inter molecular forces or cohesive forces between the particles of liquid.

Surface tension decreases with increase in temperature as the forces among particles decrease due to increase in kinetic energy.

d) Vapor pressure: Vapor pressure of a liquid  is defined as the pressure exerted by the vapors  in equilibrium with the solution at a particular temperature.

Vapor pressure increases with increase in temperature as the forces among particles decrease ad more particles can escape as vapors.

e) Evaporation is the the process in which liquid changes into gaseous state below its boiling point.

Evaporation increases with increase in temperature as the forces among particles decrease ad more particles can escape as vapors.