A solution contains 20 g sodium chloride in `95cm^(3)` solution. The density of solution is 1.25 g `cm^(-3) g cm^(-3)`. What is the mass present of NaCI ?

Explanation

To solve the problem of finding the mass percentage of sodium chloride (NaCl) in the solution, we will follow these steps:

### Step 1: Calculate the mass of the solution
We know that the density of the solution is given as \(1.25 \, \text{g/cm}^3\) and the volume of the solution is \(95 \, \text{cm}^3\). We can use the formula for density:

\[ \text{Density} = \frac{\text{Mass}}{\text{Volume}} \]

Rearranging this formula to find the mass of the solution gives us:

\[ \text{Mass} = \text{Density} \times \text{Volume} \]

Substituting the values:

\[ \text{Mass} = 1.25 \, \text{g/cm}^3 \times 95 \, \text{cm}^3 \]

Calculating this:

\[ \text{Mass} = 118.75 \, \text{g} \]

### Step 2: Calculate the mass percentage of NaCl
The mass percentage of NaCl in the solution can be calculated using the formula:

\[ \text{Mass percentage of NaCl} = \left( \frac{\text{Mass of NaCl}}{\text{Mass of solution}} \right) \times 100 \]

We know the mass of NaCl is \(20 \, \text{g}\) and the mass of the solution is \(118.75 \, \text{g}\). Substituting these values into the formula gives:

\[ \text{Mass percentage of NaCl} = \left( \frac{20 \, \text{g}}{118.75 \, \text{g}} \right) \times 100 \]

Calculating this:

\[ \text{Mass percentage of NaCl} = \left( 0.1684 \right) \times 100 = 16.84\% \]

### Final Answer
The mass percentage of NaCl in the solution is **16.84%**.

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