If `20 mL` of ethanol (density `=0.7893g//mL)` is mixed with `40mL` water (density `= 0.9971g//mL)` at `25^(@)C`, the final slution has density of `0.9571g//mL`. Calculate the percentage change in total volume of mixing. Also calculate the molarity of alcohol in the final solution.

Answer

`3.1 % 8.6`

Explanation

`C_(2)H_(5)OHrarrV_(1)=20 mL, d_(1)=0.7893 g//mL`
`m_(1)=15.786 g`
`H_(2)Orarr V_(2)=40 mL, d_(2) = 0.9971 g//mL`.
`m_(2)=39.884 g`
Total mass `= 55.65 g`
`d_(sol)=0.9571 g//mL`
`V_(sol) = 58.14 mL`
% change `= (60-58.14)/(60)xx100 =3.1%`
`m = (15.766xx1000)/(46xx39.884)=8.6`