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

Three layers of liquid are flowing over a fixed solid surface as shown below. The correct order of velocity of the liquid in these layers is:

Identify the correct statements from the following:
$I$. For an ideal gas,the compressibility factor is $1.0$.
$II$. The kinetic energy of $NO_{(g)}$ (molar mass $= 30 \ g \ mol^{-1}$) at $T(K)$ is $x \ J \ mol^{-1}$. The kinetic energy of $N_2O_{4(g)}$ (molar mass $= 92 \ g \ mol^{-1}$) at $T(K)$ is $2x \ J \ mol^{-1}$.
$III$. The rate of diffusion of a gas is inversely proportional to the square root of its density.

$A$ box of $1 \, L$ capacity is divided into two equal parts by a thin partition,which are filled with $2 \, g$ of $H_2$ and $16 \, g$ of $CH_4$ respectively. The temperature of each part is $T$. The pressure in each part is $P$. If the partition is removed,the total pressure will be:

$A$ fixed mass '$m$' of a gas is subjected to a transformation of states from $K$ to $L$ to $M$ to $N$ and back to $K$ as shown in the figure.
$1.$ The succeeding operations that enable this transformation of states are:
$(A)$ Heating,cooling,heating,cooling
$(B)$ Cooling,heating,cooling,heating
$(C)$ Heating,cooling,cooling,heating
$(D)$ Cooling,heating,heating,cooling
$2.$ The pair of isochoric processes among the transformation of states is:
$(A)$ $K$ to $L$ and $L$ to $M$
$(B)$ $L$ to $M$ and $N$ to $K$
$(C)$ $L$ to $M$ and $M$ to $N$
$(D)$ $M$ to $N$ and $N$ to $K$
Give the answer for question $1$ and $2$.

$A$ $x : 1$ molar mixture of $He$ and $CH_4$ is contained in a vessel at $20 \ bar$ pressure. Due to a hole in the vessel,the gas mixture leaks out. If the composition of the mixture effusing out initially is $8 : 1$,then the value of $x$ will be