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

First, we need to calculate the mass of 1 mole of water (H₂O). The molecular weight of water is 18 g/mol, so 1 mole of water weighs 18 g.

The total mass of the solution is the mass of "X" plus the mass of water, which is 2 g + 18 g = 20 g.

We can calculate the mass percent of "X" in the solution with the following formula:

$$\text{Mass percent of "X"}=\left(\frac{\text{mass of "X"}}{\text{total mass of solution}}\right)\times 100\%$$

Substitute the given values into the formula :

$$\text{Mass percent of "X"}=\left(\frac{2\text{g}}{20\text{g}}\right)\times 100\%=10\%$$

Therefore, Option B, $10\%$, is the correct answer.