The density of `3M` solution of `NaCl` is `1.25 g mL^(-1)`. The molality of the solution is

Explanation

To find the molality of a 3M solution of NaCl with a density of 1.25 g/mL, we can follow these steps:

### Step 1: Calculate the mass of the solution
Given that the density of the solution is 1.25 g/mL, we can calculate the mass of 1 liter (1000 mL) of the solution.

\[ \text{Mass of solution} = \text{Density} \times \text{Volume} = 1.25 \, \text{g/mL} \times 1000 \, \text{mL} = 1250 \, \text{g} \]
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