How do you solve this problem?

Question

What is the percent by volume of isopropyl alcohol in a solution that contains 19 mL of isopropyl alcohol in 1.9 L of water?

Answer 1

Percent volume is volume of solute (that's the isopropyl alcohol) divided by volume of solution (that's the volume of the isopropyl alcohol PLUS the water), then multiplied by 100 (to turn to percent). Of course to make this work, the units need to match so you can either turn 19 mL into 0.019 L or you can turn 1.9 L into 1900 mL. So, how about the later:

19/(1900+19) = 0.0099 and 0.0099(100) = 0.99% isopropyl alcohol by volume.