54 g of sodium chloride is dissolved in 100 g of water at 293 K. Find its concentration at this temperature.

Options

A. `35 %`
B. `16 %`
C. `84 %`
D. `10 %`

Explanation

To find the concentration of sodium chloride (NaCl) in a solution, we can follow these steps:

### Step 1: Identify the mass of the solute and solvent
- Mass of the solute (NaCl) = 54 g
- Mass of the solvent (water) = 100 g

### Step 2: Calculate the mass of the solution
The mass of the solution is the sum of the mass of the solute and the mass of the solvent.
\[ \text{Mass of solution} = \text{Mass of solute} + \text{Mass of solvent} = 54 \, \text{g} + 100 \, \text{g} = 154 \, \text{g} \]

### Step 3: Calculate the concentration
Concentration is calculated using the formula:
\[ \text{Concentration} = \left( \frac{\text{Mass of solute}}{\text{Mass of solution}} \right) \times 100 \]
Substituting the values we have:
\[ \text{Concentration} = \left( \frac{54 \, \text{g}}{154 \, \text{g}} \right) \times 100 \]

### Step 4: Perform the calculation
Calculating the fraction:
\[ \frac{54}{154} \approx 0.3506 \]
Now, multiplying by 100 to get the percentage:
\[ 0.3506 \times 100 \approx 35.06\% \]
Rounding to two decimal places, the concentration is approximately 35%.

### Final Answer
The concentration of sodium chloride in the solution is **35%**.

---