Question

c) to make 550 ml of a 12% (by volume, v/v%) aqueous ethylene glycol solution, one must measure out ml of ethylene glycol and add enough water to make ml of the solution.

Explanation:

Step1: Recall the formula for volume percent

The formula for volume percent (\(v/v\%\)) is \(v/v\%=\frac{\text{volume of solute}}{\text{volume of solution}}\times100\). We know the volume of the solution (\(550\space mL\)) and the volume percent (\(12\%\)), and we need to find the volume of the solute (ethylene glycol).

Step2: Rearrange the formula to solve for volume of solute

Rearranging the formula: \(\text{volume of solute}=\frac{v/v\%\times\text{volume of solution}}{100}\). Substitute \(v/v\% = 12\) and \(\text{volume of solution}=550\space mL\) into the formula.
\(\text{volume of solute}=\frac{12\times550}{100}\)

Step3: Calculate the volume of solute

First, calculate \(12\times550 = 6600\), then divide by \(100\): \(\frac{6600}{100}=66\space mL\). The volume of the solution is given as \(550\space mL\), so we add enough water to make \(550\space mL\) of the solution.

Answer:

The volume of ethylene glycol is \(66\space mL\) and the volume of the solution is \(550\space mL\), so the answers are \(66\) and \(550\) respectively.