The mole fraction of co2 in a certain solution with h2o as the solvent is 3.6 * 10-4. What is the % mass of co2 in this solution?

The % mass of CO₂ in this solution is 0.088%

Explanation:

1) Basis

Assume 100 moles of solution

2) Number of moles of CO₂ (solute)

number of moles of solute = mole fraction * number of moles of solution

3.6 * 10⁻⁴ * 100 = 0.036 moles of CO₂

3) Number of moles of H₂O (solvent)

mole fraction of solvent = moles of solution - moles of solvent

number of moles of solvent = 100 - 0.036 = 99.964 moles of H₂O

4) Mass of solution

a) Mass = number of moles * molar mass

b) Mass of CO₂ = 0.036 mol * 44.01 g/mol = 1.584 g

c) Mass of H₂O = 99.964 mol * 18.015 g/mol = 1,800.85 g

d) Mass of solution = mass of solute + mass of solvent = 1.584 g + 1,800.85 g = 1,802.435 g

5) Percent mass of CO₂, %

% = (mass of solute / mass of solution) * 100 =

% = (1.584 g / 1,802.435g) * 100 = 0.088% ← answer