Maximum number of bromine atoms present in the final product $P$ upon complete bromination are

A cubic structure is formed where atoms of element $X$ are occupied at corner of cube and also at face centers. Atoms of element $Y$ are present at body center and at the edge centers. If all the atoms are removed along a plane passing through the middle of the cube (bisecting the four edges), the formula will become

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?