Question

Ethanol, $C_2{H}_{5}OH$, is the substance commonly called alcohol. The density of liquid alcohol is 0.7893 g/ml 293 K. if 1.2 moles of ethanol are needed for a particular experiment, what volume of ethanol should be measured out?

• A. 55 ml
• B. 58 ml
• C. 70 ml
• D. 79 ml

Answer 1

Answer: (C)

70 ml

Molar mass of ethanol $C_2{H}_{5}OH$ = 12x2 + 1x6 + 1x16 = 46 g/mol

Mass = moles x molar mass

Mass of ethanol required = 1.2 x 46 = 55.2 g

Volume = mass/density

Volume required = 55.2/0.7893

= 70 ml