Question

A 2.00 M solution of CaCl2 (111 g/mol) in water has a density of 1.17 g/mL. What is the mole fraction of CaCl2? Enter your answer with 4 decimal places. Hint: Start with 1.00 L of solution.

Answer 1

Answer:

0.03586

Explanation:

Given data

2M solution means 2 moles of Cacl2 in 1 L of solution.

mass of solution = 1000mL×1.17 g/mL= 1170g

mass of CaCl2= 2mole×111 g/mol =222g

mass of water= 1170-222=968g

moles of water= 968/18= 53.77 moles

mole fraction of CaCl2= $\frac{moles of CaCl_2}{moles of CaCl_2+moles of water}$

mole fraction of CaCl2= $\frac{2}{2+53.77}$

=0.03586