Question

Determine the mole fraction of ch3oh and h2o in a solution prepared by dissolving 5.5 gm of alcohol in 40 gm of h2o. M of h2o is 18 and M of ch3oh is 32.

Answer 1

Answer:-

Given:

Mass of Alcohol in grams (m) = 5.5 gms.

Molar mass of Alcohol (M) = 32 g/mol.

We know that,

$\sf{Number \: of \: moles(n) = \frac{Mass \: in \: grams(m)}{Molar \: mass(M)}}$

→ Number of moles of Alcohol = (5.5)/32.

→ Number of moles of Alcohol = 0.17 mol.

Mass of Water in grams(m) = 40 gms.

Molar mass of Water(M) = 18 g/mol.

→ Number of moles of water = 40/18

→ Number of moles of water = 2.22 mol.

Total number of moles = 0.17 + 2.22 = 2.39 mol.

Now,

$\sf{Mole\: fraction \:of \: Alcohol = \frac{Number\: of \:moles\: of \:Alcohol}{Total \:number\: of\: moles}}$

$→\sf{Mole \: fraction \: of \: Alcohol = \frac{0.17}{2.39}}$

$\sf{Mole\: fraction\: of \:Water =\frac {Number\: of\: moles \:of \: water}{Total\: number \:of\: moles}}$

$→\sf{Mole \: fraction \: of \: Water = \frac{2.22}{2.39}}$