Question

What is the percent by volume of isopropyl alcohol in a solution made by mixing 120 mL of the alcohol with enough water to make 350 mL of solution?

Answer 1

Answer: The percent by volume of isopropyl alcohol in a solution made by mixing 120 mL of the alcohol with enough water to make 350 mL of solution is 25.5%.

Explanation:

Given: Volume of solute = 120 mL

Volume of solvent = 350 mL

Now, total volume of the solution is as follows.

$V_{total} = V_{solute} + V_{solvent}\\= 120 mL + 350 mL\\= 470 mL$

Let us assume that 100 mL of solution is taken and the amount of isopropyl alcohol present in it is as follows.

$\frac{V_{solute}}{V_{total}} \times 100 mL\\\frac{120 mL}{470} \times 100 mL\\= 25.53 mL$

Hence, there is 25.53 mL isopropyl alcohol is present in 100 mL of solution. Therefore, %v/v is calculated as follows.

$Percent (v/v) = \frac{25.53 mL}{100 mL}\\= 25.5%$

Thus, we can conclude that the percent by volume of isopropyl alcohol in a solution made by mixing 120 mL of the alcohol with enough water to make 350 mL of solution is 25.5%.