# Calculate the Percent by Volume of a Solution

To calculate the percent by volume of a solution, we need to understand the basic concept and formula involved. In this case, we are looking at a solution that is formed by mixing 25 mL of isopropanol with 45 mL of water. The total volume of the solution would be 25 mL + 45 mL = 70 mL.

The percent by volume of a solute in a solution is calculated by dividing the volume of the solute by the total volume of the solution and then multiplying by 100. This gives us the percentage of the solute in the overall solution.

Using the given volumes, the calculation for the percent by volume of isopropanol in this solution would be as follows:

**Percent by volume of isopropanol = (Volume of isopropanol / Total volume of solution) x 100**

Plugging in the values, we get:

**Percent by volume of isopropanol = (25 mL / 70 mL) x 100 = 35.71%**

Therefore, when you mix 25 mL of isopropanol with 45 mL of water, the resulting solution will have approximately 35.71% isopropanol by volume. It's important to note that this calculation assumes the volumes are additive, which may not always be the case.