Question
Chemistry Question on Chemical Kinetics
If benzene in solution containing 30% by mass in carbon tetrachloride, calculate the mole fraction of benzene.
A
(A) 0.412
B
(B) 0.326
C
(C) 0.529
D
(D) 0.458
Answer
(D) 0.458
Explanation
Solution
Explanation:
Assume the mass of benzene be 30 g in the total mass of the solution of 100 g. Mass of CCl4=(100−30)g=70 gMolar mass of benzene (C6H6)=(6×12+6×1)gmol−1=78 g mol−1Therefore, Number of moles of C6H6=MassMolar Mass=3078 mol=0.3846 molMolar mass of (CCl4)=(1×12+4×355) g mol−1=154 g mol−1Therefore, Number of moles of CCl4=MassMolar Mass=70154 mol=0.4545 molTherefore, Mole fraction of benzene = Number of moles of C6H6 Number of moles of C6H6+ Number of moles of CCl4=0.38460.3846+0.4545=0.458Hence, the correct option is (D).