Answer:
Mole fraction of gas is 3.9x10^-4
Step-by-step explanation:
The formula for mole fraction is;
Mole Fraction= Volume of gas / volume of gas in atmosphere.
Mole fraction for CO2 = volume of CO2 / Volume of CO2 in atmosphere.
Mole fraction= 390L / 10^6
Mole fraction of CO2 = 3.9x10^-4