Lattice enthalpy for $$\mathrm{NaCl}$$ is $$+788 \mathrm{~kJ} \mathrm{~mol}^{-1}$$ and $$\Delta H_{\text {hyd }}^{\circ}=-784 \mathrm{~kJ} \mathrm{~mol}^{-1}$$. Enthalpy of solution of $$\mathrm{NaCl}$$ is
At $$500 \mathrm{~K}$$, for a reversible reaction $$A_2(g)+B_2(g) \rightleftharpoons 2 A B(g)$$ in a closed container, $$K_C=2 \times 10^{-5}$$. In the presence of catalyst, the equilibrium is attaining 10 times faster. The equilibrium constant $$K_C$$ in the presence of catalyst at the same temperature is
A weak acid with $$\mathrm{p} K_a ~5.9$$ and weak base with $$\mathrm{p} K_b ~5.8$$ are mixed in equal proportions. $$\mathrm{pH}$$ of the resulting solution is
Temperature of $$25^{\circ} \mathrm{C}$$ in Fahrenheit and Kelvin scale respectively are