List of top Chemistry Questions on Chemical equilibria

Observe the following reaction \[ A(g) + B(g) \rightleftharpoons C(g) + D(g) \] In a \(1\,L\) closed flask, \(2\) moles of \(A(g)\) and \(1\) mole of \(B(g)\) were taken and heated to temperature \(T(K)\). At equilibrium, the concentration of \(C(g)\) is thrice the concentration of \(B(g)\). What is the value of \(K_c\)?
The dissociation constants of \(H_2A\) are \[ K_{a1}=6\times10^{-2} \quad \text{and} \quad K_{a2}=6\times10^{-5} \] respectively. At equilibrium, \[ [A^{2-}] = [H_2A] \] What is the approximate concentration of \(H^+\) at equilibrium?
Observe the following reaction \(A(g) + B(g) \rightleftharpoons C(g)\). In a 1L closed flask, 2 moles of \(A(g)\) and 1 mole of \(B(g)\) were taken and heated to T(K). At equilibrium, the concentration of \(B(g)\) is equal to twice the equilibrium concentration of \(C(g)\). What is the value of \(K_c\)?
In the reaction given below, water behaves as \(NH_3 + H_2O \rightleftharpoons NH_4^+ + OH^-\)
At \(T(K)\), in a 10 L flask, the following equilibrium is established:
\(2SO_{2}(g)+O_{2}(g)\rightleftharpoons 2SO_{3}(g)\).
The value of \(K_{c}\) for this reaction is 100. At equilibrium, the number of moles of \(SO_{3}(g)\) is equal to twice the number of moles of \(SO_{2}(g)\). What is the number of moles of \(O_{2}(g)\) at equilibrium?
One mole of $A(g)$ was taken in a 1L closed flask and heated to T(K). At equilibrium, the concentration of $A(g)$ is equal to four times the equilibrium concentration of $B(g)$. What is $K_c$ for $A(g) \rightleftharpoons B(g) + C(g)$?
The conjugate base of $\text{H}_{2}\text{PO}_{4}^{-}$ is
For the reaction $2HI(g)\rightleftharpoons H_{2}(g)+I_{2}(g)$, the correct expression relating the degree of dissociation ($\alpha$) of HI and equilibrium constant $K_{p}$ is
For the reaction $\text{N}_2\text{(g)} + 3\text{H}_2\text{(g)} \rightleftharpoons 2\text{NH}_3\text{(g)}$, the relation between $K_p$ and $K_c$ is
Which one of the pairs will form a buffer solution?
Consider the equilibrium reactions:

\(H_3PO_4 \rightleftharpoons H^+ + H_2PO_4^-\) \((K_1)\)
\(H_2PO_4^- \rightleftharpoons H^+ + HPO_4^{2-}\) \((K_2)\)
\(HPO_4^{2-} \rightleftharpoons H^+ + PO_4^{3-}\) \((K_3)\)

The equilibrium constant, \(K_c\), for the following dissociation:

\(H_3PO_4 \rightleftharpoons 3H^+ + PO_4^{3-}\)

is:
The conjugate base of \(NH_4^+\) is:
A reaction gas mixture contains \(50\%\), \(30\%\), \(20\%\) of \(A\), \(B\) and \(C\) by volume, respectively. The mixture undergoes the following reactions.
\[ 1.\quad A+2B \longrightarrow P_1 \] \[ 2.\quad 4P_1+3C \longrightarrow P_2 \] \(P_1\) and \(P_2\) are two products of the reactions. Choose the correct answer if the reaction completes.