Chemistry - Mole Concept Question with Solution | TestHub

Number of moles$=\frac{\mathrm{w}\mathrm{e}\mathrm{i}\mathrm{g}\mathrm{h}\mathrm{t} \text{in gm}}{\text{atomic weight}}$
Number of moles$\mathrm{Li}=\frac{70}{1000\times 7}={10}^{-2}$
Number of moles of$\mathrm{Na}=\frac{230}{1000\times 23}\times ={10}^{-2}$
Amount of energy = moles$\times$energy needed for 1 mole.
So the amounts of energies required for$10^{-2}$mole each of Li and Na are as follows
For sodium$=520\times {10}^{-2} \mathrm{kJ}=5200 \mathrm{J}$
For Lithium$=495\times {10}^{-2} \mathrm{kJ}=4950 \mathrm{J}$respectively.