Final answer:
The density of solid H2 can be calculated based on the van der Waals constant 'b' and the given density of N2. Assuming the same percentage void and close packing, the density of solid H2 is proportional to the 'b' constant ratio. The calculated density of solid H2 is 0.625 g cm-3.
Step-by-step explanation:
To determine the density of solid H2, we can use the van der Waals constant 'b' which is a measure of the excluded volume per mole of gas caused by the finite volume occupied by the gas molecules. Given that the density of solid N2 is 1 g cm-3 and assuming the molecules in the solid are close-packed with the same percentage void, we can assume that the ratio of the densities of the two solids will be proportional to the ratio of their van der Waals 'b' constants, given that the densities are affected by how closely the molecules can pack together.
The van der Waals constant 'b' for N2 and H2 are given as 0.04 L mol-1 and 0.025 L mol-1 respectively. The density of solid N2 is given as 1 g cm-3. If we assume close packing and the same percentage void, the relative density would be proportional to their 'b' constants. Therefore:
Density of H2 = Density of N2 * (b of H2 / b of N2)
Density of H2 = 1 g cm-3 * (0.025 L mol-1 / 0.04 L mol-1) = 0.625 g cm-3
The calculated density of solid H2 would thus be 0.625 g cm-3, which corresponds to option (a).