In which of the following cases does the reaction proceed towards completion?

In a reversible reaction $A \overset{k_1}{\underset{k_2}{\longleftrightarrow}} B$,the initial concentrations of $A$ and $B$ are $a$ and $b$,and the equilibrium concentrations are $(a - x)$ and $(b + x)$ respectively. Express $x$ in terms of $k_1, k_2, a$,and $b$.

For a reversible reaction,if the concentration of the reactants is reduced to half,the equilibrium constant will be.........

Mark the correct statement in a reversible reaction.

In which of the following reactions,the concentration of product is higher than the concentration of reactant at equilibrium? $(K = \text{equilibrium constant})$

Which of the following nitrogen oxides is the most stable?