At 500 K , equilibrium constant, $\mathrm{K}_{\mathrm{c}}$, for the following reaction is 5.

$$\frac{1}{2} \mathrm{H}_2(\mathrm{~g})+\frac{1}{2} \mathrm{I}_2(\mathrm{~g}) \rightleftharpoons \mathrm{HI}(\mathrm{g})$$

What would be the equilibrium constant $\mathrm{K}_{\mathrm{c}}$ for the reaction?

$$2 \mathrm{HI}(\mathrm{g}) \rightleftharpoons \mathrm{H}_2(\mathrm{~g})+\mathrm{I}_2(\mathrm{~g})$$

In which of the following reactions, the equilibrium remains unaffected on addition of small amount of argon at constant volume?

For the reaction $\mathrm{N}_2 \mathrm{O}_4(\mathrm{~g}) \rightleftharpoons 2 \mathrm{NO}_2(\mathrm{~g})$, the value of K is 50 at 400 K and 1700 at 500 K . Which of the following option(s) is/are correct?

At a particular temperature and atmospheric pressure, the solid and liquid phases of a pure substance can exist in equilibrium. Which of the following term defines this temperature?

The ionisation of hydrochloric acid in water is given below

$$\mathrm{HCl}(\mathrm{aq})+\mathrm{H}_2 \mathrm{O}(l) \rightleftharpoons \mathrm{H}_3 \mathrm{O}^{+}(\mathrm{aq})+\mathrm{Cl}^{-}(\mathrm{aq})$$

Label two conjugate acid-base pairs in this ionisation.