What is the mole fraction of urea,CO(NH₂)₂,in a solution prepared by dissolving 6.8 g of urea in 33.5 g of methanol,CH₃OH? A) 0.83 B) 0.17 C) 0.098 D) 0.90 E) 0.28

Question

Quizplus · Accepted Answer

1. Calculate the number of moles of urea:

n(urea) = mass/molar mass
n(urea) = 6.8 g / 60.06 g/mol 
n(urea) = 0.113 mol

2. Calculate the number of moles of methanol:

n(methanol) = mass/molar mass
n(methanol) = 33.5 g / 32.04 g/mol 
n(methanol) = 1.046 mol

3. Calculate the total number of moles in the solution:

n(total) = n(urea) + n(methanol) 
n(total) = 0.113 mol + 1.046 mol 
n(total) = 1.159 mol

4. Calculate the mole fraction of urea:

X(urea) = n(urea) / n(total) 
X(urea) = 0.113 mol / 1.159 mol 
X(urea) = 0.098

Thus, the mole fraction of urea is 0.098, which is approximately 0.10. Therefore, the best choice is C.

What Is the Mole Fraction of Urea,CO(NH2)2, in a Solution

What Is the Mole Fraction of Urea,CO(NH₂)₂,in a Solution