ANSWER
The mass of ethanol is 74.55 grams
STEP-BY-STEP EXPLANATION:
The % by volume of ethanol is 95%
The density of ethanol is 0.789
Let the mass of ethanol be m
To find the mass of ethanol, we will need to apply the density formula
[tex]\text{ Density = }\frac{mass}{\text{volume}}[/tex]The next step is to find the volume of the ethanol in the alcohol by using the below formula
[tex]\begin{gathered} \text{ \% by volume = }\frac{volume\text{ of solute}}{\text{volume of solution}} \\ \end{gathered}[/tex]Assuming 100mL of water was used
% by volume is 95%
Hence, we can calculate the volume of ethanol by using the above formula
[tex]\begin{gathered} 0.95\text{ = }\frac{volume\text{ of ethanol}}{100} \\ \text{Volume of ethanol = 0.95 }\times\text{ 100} \\ \text{Volume of ethanol = 95 mL} \end{gathered}[/tex]The next step is to find the mass of the ethanol
[tex]\begin{gathered} \text{Density = }\frac{mass}{\text{volume}} \\ \text{mass = density x volume} \\ \text{mass = 0.789 }\times95 \\ \text{mass = 74.955 grams} \end{gathered}[/tex]Therefore, the mass of ethanol is 74.55 grams