Calculate the mole fraction of benzene in solution containing 30% by mass in carbon tetrachloride.

Answer

0.458

Explanation

Mass of benzene in 30% solution = 30g
Mass of carbon tetrachloride `= (100 - 30) g = 70 g`
Molar mass of benzene `C_(6)H_(6)=12 xx 6 +1 xx 6=78"g mol"^(-1)`
Molar mass of carbon tetrachloride, `C Cl_(4)=12+35.5 xx 4`
` =154"g mol"^(-1)`
Moles of benzene in 30g` = (30)/(78)= 0.385` mol
Moles of carbon tetrachloride in 70 g `=(70)/(154)=0.455` mol
Total no. of moles `=0.385 +0.455 =0.840`
Mole fraction of benzene `=("No. of moles of benzene")/("Total number of moles")=(0.385)/(0.840)=0.458`