Question

10 ml of alcohol is added to water to make a volume of the solution upto 250 ml calculate the percentage by volume of alcohol in the solution​

Answer 1

Volume of water = 250 - 10 = 240 mL

10 × 100 / 240 = ~ 4.2 %

Answer 2

Explanation:

Volume of ethanol = 10 ml

Volume of solution = 100 ml

Weight of ethanol = Volume×density

= 10×0.785

= 7.85 g

Weight of solution = 100×0.9866

= 98.66 g

$Weight \: percent \: of \: ethanol = \frac{7.85}{98.66} \times 100$

= 7.95%