$A$ 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?

Select the incorrect statement using the phase diagram of a substance.

$A$ gas sample of $1.47 \ L$ was collected over water at $30 \ ^\circ C$ and $744 \ mm \ Hg$ pressure. If the weight of the gas is $1.98 \ g$,what is the molar mass of the gas? (Assume the vapor pressure of water at $30 \ ^\circ C$ is $31.8 \ mm \ Hg$)

Two flasks of equal volume are filled with $N_2$ gas and connected by a thin tube of negligible volume. When both flasks are immersed in boiling water,the pressure of the gas inside the system is $0.5 \, atm$. Calculate the pressure of the system when one flask is immersed in ice water and the other is kept in boiling water. (in $, atm$)

$1 \text{ mole}$ of gas $A$ and $1 \text{ mole}$ of gas $B$ at $27^{\circ} C$ were pumped into a $24.6 \ L$ volume pre-evacuated isolated flask. The catalyst coated inside the flask catalyses the following reaction $A_{(g)} + B_{(g)} \longrightarrow 2 D_{(g)}$. The kinetic energy of $D$ is $98.03 \ L \ atm$. Calculate the pressure realized at the end of the reaction. (in $atm$)

Which of the following statements is incorrect?