Question

Alcohol is commonly used as a hand sanitizer and as an antiseptic for small cuts. It is sold as 70 % (v/v) solution of isopropyl alcohol in water. What volume of isopropyl alcohol is used to make 500 mL of rubbing alcohol?

• A. 70 mL
• B. 200 mL
• C. 450 mL
• D. 350 mL

Answer 1

The correct option is D 350 mL

Given: volume of alcoholic solution is 500 mL
%$\frac{v}{v}$ = $\frac{\text{Volume of the component (mL)}}{\text{Volume of the solution (mL)}}\times 100$
$\Rightarrow 70=\frac{\text{volume of the isopropyl alcohol (mL)}}{\text{500 mL}}\times 100$
Volume of isopropyl alcohol = $70\times 5=350$ mL