$A$ and $B$ are ideal gases. The molecular weights of $A$ and $B$ are in the ratio of $1: 4$. The pressure of a gas mixture containing equal weights of $A$ and $B$ is $P \text{ atm}$. What is the partial pressure (in $\text{atm}$) of $B$ in the mixture?

At $STP$,what is the actual volume occupied by the molecules of $1 \, \text{mol}$ of water vapor (i.e.,$\text{Avogadro's number} \times \text{volume of one molecule}$)?

The three states of matter are the result of what?

Adiabatic demagnetisation is a technique used for

$A$ beaker containing a mixture of liquid $A$ and liquid $B$,in equilibrium with each other,is cooled very slowly. If point '$D$' on the graph is where solidification of both liquids is complete,how many different phases co-exist along line '$C D$' if freezing points of liquid $B$ and liquid $A$ are $-25^{\circ} C$ and $-78^{\circ} C$ respectively?

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