What is the number of neighbouring spheres for any particle in the fcc crystal lattice ?

Identify a solution which contains solid as solute and liquid as solvent.

A solution of $50$g of solute 'X' is dissolved in $150$ g of 'Y' solvent boils at $357.27$ K. What is the molar mass of solute?
(Given $K_b$ and boiling point pure solvent is $2.77$ K kg/mol and $350.06$ K respectively.)

The partial pressure of a gas at $25^\circ$C is $0.18$ atm, calculate the concentration of the gas dissolved at the same temperature,
If $K_H$ is $0.15\ \text{mol dm}^{-3}\ \text{atm}^{-1}$