What is the percent by volume of isopropyl alcohol in a solution made by dissolving 18.9mL of isopropyl alcohol in 412mL of water?
1 Answer
Explanation:
We express a solution's volume by volume percent concentration,
In essence, all you have to do to determine a solution's volume by volume percent concentration is figure out how many milliliters of solute you get in
In your case, you know that you get
V_"total" = V_"solute" + V_"solvent"
V_"total" = "18.9 mL" + "412 mL" = "430.9 mL"
of solution. In order to find the solution's
100 color(red)(cancel(color(black)("mL solution"))) * overbrace("18.9 mL isopropyl alcohol"/(430.9color(red)(cancel(color(black)("mL solution")))))^(color(blue)("the solution's composition")) = "4.39 mL isopropyl alcohol"
Now all you have to do is replace the
"% v/v" = "4.39 mL isopropyl alcohol"/"100 mL solution" = color(green)(|bar(ul(color(white)(a/a)color(black)(4.39%)color(white)(a/a)|)))
The answer is rounded to three sig figs.