Question Video: Calculating the Volume of Solute from a Percentage v/v Concentration Chemistry

A 0.75 L bottle of vinegar contains 4% (v/v) of ethanoic acid. What volume of ethanoic acid does the bottle of vinegar contain? Give your answer to two decimal places.

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Video Transcript

A 0.75-liter bottle of vinegar contains four percent volume by volume of ethanoic acid. What volume of ethanoic acid does the bottle of vinegar contain? Give your answer to two decimal places.

The question asks what volume of ethanoic acid is contained in a bottle of vinegar, and we are told the volume of the bottle of vinegar is 0.75 liters. We are also told the concentration of ethanoic acid in the vinegar is four percent volume by volume. Concentration of a solution in terms of a percentage is equal to the amount of solute in the solution divided by the amount of solution multiplied by 100 percent. A volume-by-volume percent concentration will therefore be the volume of solute in the solution divided by the volume of the solution multiplied by 100 percent.

Before doing this calculation, we need to first identify that ethanoic acid is the solute and vinegar, the solution. To find the volume of solute, or ethanoic acid, which is what we were asked, we first need to know the percent concentration of the solution and the volume of the solution. We are given the percent concentration, four percent volume by volume, and we were given the volume of the solution, 0.75 liters. Let’s substitute the two values that we know into the equation.

We must now rearrange the equation to make the volume of solute the subject of the formula. After rearranging, we get volume of solute is equal to four percent multiplied by 0.75 liters divided by 100 percent. The numerical portion of the answer that we get is 0.03. The percent units cancel, and we are left with liters as the unit. This answer has two decimal places, which is what we were asked for. Finally, “What volume of ethanoic acid does the bottle of vinegar contain?” 0.03 liters.