What is the mole fraction of N in a solution prepared by dissolving 16.0 g of N in 250.0 g of water? The density of the resulting solution is 0.974 g/mL.
A)0.0640
B)0.940
C)0.0635
D)0.922
E)16.8

Question

What is the mole fraction of N  in a solution prepared by dissolving 16.0 g of N  in 250.0 g of water? The density of the resulting solution is 0.974 g/mL.
A)0.0640 
B)0.940 
C)0.0635 
D)0.922 
E)16.8

Quizplus · Accepted Answer

Step 1: Calculate the moles of Nitrogen (N2) in the solution.

Moles of N2 = mass / molar mass
Molar mass of N2 = 28.0 g/mol
Mass of N2 = 16.0 g

Moles of N2 = 16.0 g / 28.0 g/mol
Moles of N2 = 0.571 mol

Step 2: Calculate the moles of water in the solution.

Volume of water = 250.0 g / 0.974 g/mL
Volume of water = 256.22 mL

Moles of water = volume / molar volume
Molar volume of water = 18.015 g/mol
Volume of water = 256.22 mL / 1000 mL/L
Volume of water = 0.25622 L

Moles of water = 0.25622 L x 1000 mL/L / 18.015 g/mol
Moles of water = 14.207 mol

Step 3: Calculate the mole fraction of Nitrogen (N2) in the solution.

Mole fraction of N2 = moles of N2 / (moles of N2 + moles of water)
Mole fraction of N2 = 0.571 mol / (0.571 mol + 14.207 mol)
Mole fraction of N2 = 0.03962

Mole fraction of N2 = 0.0635 (rounded to four significant figures)

Therefore, the answer is (C) 0.0635.

What Is the Mole Fraction of N in a Solution