pH of 0.05 M aqueous solution of diethyl amine is 10 . The value of equilibrium constant is

The observed molar mass determined for $\mathrm{Na}_2 \mathrm{SO}_4$ by freezing point depression method is $50.0 \mathrm{~g} / \mathrm{mol}$. The molecular weight of $\mathrm{Na}_2 \mathrm{SO}_4$ is 142 . What will be the degree of dissociation $\alpha$ for $\mathrm{Na}_2 \mathrm{SO}_4$ in water?

Copper is to be electrodeposited on a nickel block of $(20 \times 5) \mathrm{cm}^2$ area by using $\mathrm{CuSO}_4$ as electrolyte. How much quantity of electricity is needed to deposit a 3.6 $\mu \mathrm{m}$ layer of copper?

[Atomic weight of $\mathrm{Cu}=63.5 \mathrm{~mol}^{-1}$ Density of $\mathrm{CuSO}_4=8.9 \mathrm{~g} / \mathrm{cc}$ ]

The half-life of a first order reaction varies with temperature according to