JEE Main 2023 — Some Basic Concepts Of Chemistry Question with Solution

A. 16 g of $\mathrm{C}{\mathrm{H}}_4(\mathrm{g})$

The molar mass of $\mathrm{C}{\mathrm{H}}_4$ (Methane) is 16 g/mol. Therefore, 16 g of $\mathrm{C}{\mathrm{H}}_4$ is equivalent to 1 mole of $\mathrm{C}{\mathrm{H}}_4$. Furthermore, each molecule of $\mathrm{C}{\mathrm{H}}_4$ has 10 electrons (6 from Carbon and 4 from Hydrogen). As a result, 1 mole of $\mathrm{C}{\mathrm{H}}_4$ (or $6.022\times 10^{23}$ molecules of $\mathrm{C}{\mathrm{H}}_4$) would have $10\times 6.022\times 10^{23}=60.2\times 10^{23}$ electrons. This matches with (II).

B. 1 g of ${\mathrm{H}}_2(\mathrm{g})$

The molar mass of ${\mathrm{H}}_2$ (Hydrogen) is 2 g/mol. Therefore, 1 g of ${\mathrm{H}}_2$ is equivalent to 0.5 moles of ${\mathrm{H}}_2$. The volume that a given quantity of gas occupies is proportional to the number of moles of gas. At standard temperature and pressure (STP), 1 mole of any ideal gas occupies 22.4 liters. Therefore, 0.5 moles of gas would occupy $0.5\times 22.4=11.2$ liters. The closest match is (IV) with 11.4 liters (the small discrepancy may be due to rounding or slightly different conditions than STP).

C. 1 mole of ${\mathrm{N}}_2(\mathrm{g})$

The molar mass of ${\mathrm{N}}_2$ (Nitrogen) is 28 g/mol. Therefore, 1 mole of ${\mathrm{N}}_2$ weighs 28 g. This matches with (I).

D. 0.5 mol of $\mathrm{S}{\mathrm{O}}_2(\mathrm{g})$

The molar mass of $\mathrm{S}{\mathrm{O}}_2$ (Sulfur Dioxide) is 64 g/mol. Therefore, 0.5 moles of $\mathrm{S}{\mathrm{O}}_2$ weigh $0.5\times 64=32$ g. This matches with (III).

Thus, the correct matches are:

A - II

B - IV

C - I

D - III