For the reaction $A + B \rightleftharpoons C + D$ at $250^\circ C$ in a $1 \ L$ vessel,the initial concentration of $A$ is $3$ and $B$ is $n$. If the equilibrium concentration of $C$ is equal to the equilibrium concentration of $B$,what is the equilibrium concentration of $D$?

In a reaction,$A + B \rightleftharpoons C + D$,$40 \%$ of $B$ has reacted at equilibrium,when $1 \ mol$ of $A$ was heated with $1 \ mol$ of $B$ in a $10 \ L$ closed vessel. The value of $K_C$ is

Given below are two statements:
Statement $I$: $A$ catalyst cannot alter the equilibrium constant $(K_{C})$ of the reaction,temperature remaining constant.
Statement $II$: $A$ homogenous catalyst can change the equilibrium composition of a system,temperature remaining constant.
In the light of the above statements,choose the correct answer from the options given below:

$5 \ moles$ of $SO_2$ and $5 \ moles$ of $O_2$ are allowed to react. At equilibrium,it was found that $60\%$ of $SO_2$ is used up. If the partial pressure of the equilibrium mixture is $1 \ atm$,the partial pressure of $O_2$ is (in $atm$)

At high temperature,$2 \, \text{mol}$ of $NH_3$ is placed in a $500 \, \text{mL}$ vessel. For the decomposition reaction $2NH_{3(g)} \rightleftharpoons N_{2(g)} + 3H_{2(g)}$,if $1 \, \text{mol}$ of $NH_3$ remains at equilibrium,then $K_c$ is equal to:

Attainment of the equilibrium $A_{(g)} \rightleftharpoons 3C_{(g)} + 2B_{(g)}$ gave the following graph. Find the correct option. $(\text{Percentage dissociation} = \text{fraction dissociated} \times 100)$