Answer:
[CO₂] = 375 ppm
Step-by-step explanation:
We can determine the concentration in value of ppm
ppm = mass of solute (mg) / mass of solution (kg)
Solution: atmosphere
Solute: CO₂
We convert the mass of CO₂ from g to mg → 0.1875 g . 1000 mg / 1g = 187.5 mg
We convert the mass of the atmosphere from g to kg: 500 g . 1 kg/1000g = 0.500 kg
ppm = 187.5 mg / 0.500kg = 375