JEE Main 2024 — Some Basic Concepts Of Chemistry Question with Solution

To find the molarity of the aqueous solution, we need to calculate the number of moles of NaCl and then divide it by the volume of the solution in liters.

First, determine the molar mass of NaCl:

$$\text{Molar mass of NaCl}=\text{Molar mass of Na}+\text{Molar mass of Cl}=23+35.5=58.5\text{g/mol}$$

Next, calculate the moles of NaCl:

$$\text{Moles of NaCl}=\frac{5.85\text{g}}{58.5\text{g/mol}}=0.1\text{mol}$$

Now, convert the volume of the solution from milliliters to liters:

$$500\text{mL}=0.500\text{L}$$

Finally, calculate the molarity (M), which is the number of moles of solute per liter of solution:

$$M=\frac{\text{Moles of NaCl}}{\text{Volume of solution in liters}}=\frac{0.1\text{mol}}{0.500\text{L}}=0.2\text{M}$$

Therefore, the molarity of the solution is 0.2 M. The correct option is D.