Questions: What is the percent mass of potassium chloride in a solution made by adding 25 g of potassium chloride to 70.0 ml of water? - Your answer should have two significant figures. Provide your answer below:

Solution Steps

To find the percent mass of potassium chloride in the solution, we first need to determine the total mass of the solution. The total mass is the sum of the mass of potassium chloride and the mass of water.

• Mass of potassium chloride = 25 g
• Mass of water = 70.0 ml

Assuming the density of water is approximately \(1 \, \text{g/ml}\), the mass of water is:

\[ \text{Mass of water} = 70.0 \, \text{g} \]

Thus, the total mass of the solution is:

\[ \text{Total mass} = 25 \, \text{g} + 70.0 \, \text{g} = 95.0 \, \text{g} \]

The percent mass of potassium chloride in the solution is calculated using the formula:

\[ \text{Percent mass} = \left( \frac{\text{Mass of potassium chloride}}{\text{Total mass of the solution}} \right) \times 100\% \]

Substituting the known values:

\[ \text{Percent mass} = \left( \frac{25 \, \text{g}}{95.0 \, \text{g}} \right) \times 100\% = 26.3158\% \]

The problem asks for the answer to be in two significant figures. Therefore, we round 26.3158% to two significant figures:

\[ \text{Percent mass} \approx 26\% \]

Final Answer