If you have 300 mL of a 30% ethanol solution, what is the volume of ethanol in the solution?

To determine the volume of ethanol in a solution, you can use the percentage concentration to calculate the volume of the solute (ethanol in this case) in a given volume of solution.

In this scenario, you have a 30% ethanol solution, which means that 30% of the total volume of the solution is made up of ethanol.

To find the volume of ethanol in the solution, you can multiply the total volume of the solution by the percentage expressed as a decimal:

1. Convert the percentage to a decimal: 30% = 0.30.

2. Multiply the total volume of the solution (300 mL) by this decimal:

Volume of ethanol = 300 mL × 0.30 = 90 mL.

This calculation shows that there are 90 mL of ethanol in the 300 mL solution, confirming that the correct choice is indeed the volume of ethanol. Understanding how to convert percentages to decimal form and applying them to total volumes is crucial for solving similar problems in analytical chemistry.