Question

Ethanol ($C_2{H}_{5}OH$) is the substance commonly called alcohol. The density of liquid alcohol is $0.7893$ g/ml at $293$K. If $1.2$ moles of ethanol is needed for a particular experience, the volume of ethanol measured out is :

• A. $70$ ml
• B. $80$ ml
• C. $84$ ml
• D. $90$ ml

Answer 1

The correct option is A $70$ ml

The molar mass of ethanol is $46.06$ g/mol.
$1.2$ moles of ethanol corresponds to $1.2\times 46.06=55.272$ g.
The volume required is, $Volume=\frac{Mass}{Density}=\frac{55.272g}{0.7893g/ml}=70ml$.