What is the total pressure (in atm) inside a vessel containing N2 exerting a partial pressure of 0.256 atm, He exerting a partial pressure of 203 mmHg, and H2 exerting a partial pressure of 39.0 kPa?

• A. 0.75 atm
• B. 1.00 atm
• C. 0.50 atm
• D. 1.25 atm

Answer: (B)

Verified step by step guidance

1. Identify the partial pressures of each gas: N2 has a partial pressure of 0.256 atm, He has a partial pressure of 203 mmHg, and H2 has a partial pressure of 39.0 kPa.
2. Convert all partial pressures to the same unit, preferably atmospheres (atm). Use the conversion factors: 1 atm = 760 mmHg and 1 atm = 101.325 kPa.
3. Convert the partial pressure of He from mmHg to atm using the formula: \( P_{He} = \frac{203 \text{ mmHg}}{760 \text{ mmHg/atm}} \).
4. Convert the partial pressure of H2 from kPa to atm using the formula: \( P_{H2} = \frac{39.0 \text{ kPa}}{101.325 \text{ kPa/atm}} \).
5. Add the partial pressures of all gases in atm to find the total pressure: \( P_{total} = P_{N2} + P_{He} + P_{H2} \).