Question

what is the percent by volume of a solution formed by mixing 25 ml of isopropanol with 45 ml of water? ​

Answer 1

Answer:

$\mathsf\red{Given}$

$\mathsf{V_1 \: (solute \: volume)\: = \: 25ml}$

$\mathsf{V \: (volume \: of \: solution ) \: = \: solute \: + \: solvent \: = \: 25 +45= 70ml}$

so

$\mathsf{\frac{volume}{volume} \: \% \: = \: \frac{V_1}{V} \times 100}$

$\mathsf{\frac{volume}{volume} \: \% \: = \: \frac{25}{70} \times 100}$

$\mathsf{\frac{volume}{volume} \: \% \: = \: \frac{2500}{70}}$

$\mathsf{\frac{volume}{volume} \: \% \: = \: 35.71}$

$\mathsf\red{The \: answer \: should \: have \: only \: 2 \: significant \: digits}$

$\mathsf{\frac{volume}{volume} \: \% \: = \: 36\%}$