Equilibrium Tes...

For the reaction $${{\text{H}}_{\text{2}}}{\text{(g) + }}{{\text{I}}_{\text{2}}}{\text{(g)}} \rightleftharpoons {\text{2HI(g)}}$$ 
$$\rm{K_c}=66.9$$ at $$350^\circ$$C and $$\rm{K_c}=50.0$$ at $$448^\circ$$C. The reaction has:

Given the following reaction at equilibrium $$N_2 \:(g) + 3H_2 \:(g)\rightleftharpoons 2 NH_3 \:(g)$$. Some inert gas at constant pressure is added to the system. Predict which of the following facts will be affected :

A reaction in equilibrium is represented by the following equation.

In a 20 litre vessel, initially 1 mole each of $$CO,\ {H}_{2}O,\ C{O}_{2}$$ is present, then for the equilibirum of 
$$CO+{H}_{2}O\rightleftharpoons C{O}_{2}+{H}_{2}$$, which one among the following is true?

When add 0.01 M HCl in aqueous solution of acetic acid :

Which of the following is correct regarding buffer solution?

For the reaction $$A+2B\rightleftharpoons 2C+D$$, initial concentration of A is a and that of B is 1.5 times that of A. Concentration of A and D are same at equilibrium. What should be the concentration of B at equilibrium?

Which of the following can give a buffer solution?