Q. 24.4( 109 Votes )
Calculate the mole fraction of benzene in solution containing 30% by mass in carbon tetrachloride.
Let the total mass of the solution be 100 g and the mass of benzene be 30 g.
∴ Mass of carbon tetrachloride = (100 - 30)g = 70 g
Molar mass of benzene (C6H6) = (6 × 12 + 6 × 1) g mol- 1
= 78 g mol- 1
∴ Number of moles of C6H6 =30/78 mol
= 0.3846 mol
Molar mass of carbon tetrachloride (CCl4) = 1 × 12 + 4 × 35.5
= 154 g mol- 1
∴ Number of moles of CCl4= 70/154 mol
= 0.4545 mol
Thus, the mole fraction of C6H6is given as:
= 0.3846 / (0.3846 +0.4545)
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