Calculate the molality of each of the following solutions:
(a) 0.710 kg of sodium carbonate (washing soda), Na_ $\mathrm{CO}_{3},$ in 10.0 $\mathrm{kg}$ of waturated solution at $0^{\circ} \mathrm{C}$
(b) 125 $\mathrm{g}$ of $\mathrm{NH}_{4} \mathrm{NO}_{3}$ in 275 $\mathrm{g}$ of water-a mixture used to make an instant ice pack
(c) 25 $\mathrm{g}$ of $\mathrm{Cl}_{2}$ in 125 $\mathrm{g}$ of dichloromethane, $\mathrm{CH}_{2} \mathrm{Cl}_{2}$
(d) 0.372 g of tetrahydropyridine, $C_{5} \mathrm{H}_{9} \mathrm{N},$ in 125 $\mathrm{g}$ of chloroform, CHCl_{3}