Final answer:
The volume of isopropyl alcohol used to make 500 mL of rubbing alcohol is 350 mL.
Step-by-step explanation:
The volume of isopropyl alcohol in the rubbing alcohol can be calculated using the given percentage composition and the total volume of the solution. In this case, the rubbing alcohol is a 70% (v/v) solution of isopropyl alcohol.
This means that for every 100 mL of rubbing alcohol, 70 mL is isopropyl alcohol. To find the volume of isopropyl alcohol in 500 mL of rubbing alcohol, we can set up a proportion:
70 mL (isopropyl alcohol) / 100 mL (rubbing alcohol) = x mL (isopropyl alcohol) / 500 mL (rubbing alcohol)
Cross multiplying, we get:
100 * x mL = 70 * 500 mL
Simplifying, we find that x = 35,000 / 100 = 350 mL. Therefore, 350 mL of isopropyl alcohol is used to make 500 mL of rubbing alcohol.