$1.$Which of the following statement$/$s is$/$are TRUE?

I. The equilibrium constant is independent of pressure.

II$.$ Increasing pressure of gases by adding an inert gas

a$.$ I only

b$.$ II only

c$.$ I and II

d$.$ none

$2.$If we can find the composition at which $\_\_\_\_\_$ of the component is equal, then we can identify the composition of the reaction mixture at equilibrium.

a$.$ activity

b$.$ chemical potential

c$.$ reaction Gibbs energy

d$.$ physical properties

$3.$In a ternary$-$component system with one phase, the degree of freedom is

a$.1$

b$.3$

c$.2$

d$.$ none of the above

$4.$If $40\%$ alcohol, $30\%$ water, and $30\%$ benzene is prepared, what is the concentration of water in one phase?

a$.40\%$

b$.30\%$

c$.60\%$

d$.$ none of the choices