If the distance between two gas molecules becomes half,what change occurs in the London dispersion forces?

When the temperature is raised,the viscosity of liquid decreases,this is because

Why is it necessary for chemists to understand the laws that govern the physical states of matter?

The vapor pressure of water at $80\,^oC$ is $355.5\, mm\, of\, Hg$. $A$ $100\, mL$ vessel contains $O_2$ saturated with water vapor at $80\,^oC$,and the total pressure is $760\, mm\, of\, Hg$. If the contents are transferred to a $50\, mL$ vessel at the same temperature,what will be the partial pressure of $O_2$ in $mm\, Hg$?

Two statements are given below.
Statement-$I$: Viscosity of liquid decreases with increase in temperature.
Statement-$II$: The units of viscosity coefficient are Pascal sec.
The correct answer is

During winter,when taking a bath,water vapour appears. Explain the physical process.