Question

calculate the mole fraction of benzene in solution containing 30 percentage by mass in carbon tetrachloride​

Answer 1

0.4583(approx.)

Given:

30 % of benzene in tetrachloride

To Calculate:

Mole fraction of Benzene

Solving:

Calculating the molecular mass of Benzene Formula (C6H6)

= 12 g x 6 + 1 g x 6

= 72 + 6

= 78 g mol^-1

Calculating the molecular mass of Carbon Tetrachloride (CCl4)

= 12 g x 1 + 35.5 g x 4

= 12 + 142

= 154 g mol^-1

Let us assume the solution to have a weight of 100 grams

Mass of ethylene glycol =  30 grams

Calculating the mass of solvent = 100 - 30 = 70 grams

Number of moles of solute

= Mass of solution / Molecular mass of soln.

= 30 / 78

= 0.3846 mol

Calculating number of moles of solvent Carbon Tetrachloride

= 70 g / 154 g

= 0.4545 mol

Calculating total number of moles:

= 0.4545 + 0.3846

= 0.8391 mol

Calculating the mole fraction:

= nB/(nA + nB)

= 0.3846/ 0.8391

= 0.4583

Therefore, the mole fraction of Benzene is 0.4583(approx.)