Final answer:
The CO₂ gas makes up 5% of the total gas mixture used for arc welding stainless steel when the total mixture pressure is 200 kPa, with Argon at 160 kPa and Helium at 30 kPa.
Step-by-step explanation:
The subject of the question is Chemistry, particularly the concept of partial pressure in gas mixtures. To find the percentage of CO₂ gas in the mixture, we need to first determine its partial pressure. The total pressure of the gas mixture is given as 200 kPa, and we have the partial pressures of Argon and Helium as 160 kPa and 30 kPa respectively.
The partial pressure of CO₂ would be the remaining pressure after subtracting the partial pressures of Argon and Helium from the total pressure:
Total pressure of gas mixture = Pressure of Argon (Ar) + Pressure of Helium (He) + Pressure of CO₂
200 kPa = 160 kPa + 30 kPa + Pressure of CO₂
Pressure of CO₂ = 200 kPa - 160 kPa - 30 kPa
Pressure of CO₂ = 10 kPa
Now, to calculate the percentage of CO₂ in the mixture, the partial pressure of CO₂ is divided by the total pressure, then multiplied by 100:
Percentage of CO₂ = (Pressure of CO₂ / Total pressure) × 100
Percentage of CO₂ = (10 kPa / 200 kPa) × 100
Percentage of CO₂ = 5%
Therefore, CO₂ makes up 5% of the total gas mixture in the arc welding process for stainless steel.