Final answer:
The partial pressure of O₂ on top of the Matterhorn is calculated by multiplying the atmospheric pressure (0.55 atm) by the fraction of O₂ in air (20.9%), resulting in 0.115 atm.
Step-by-step explanation:
To determine the partial pressure of O₂ on top of the Matterhorn in the Swiss Alps where the atmospheric pressure is 0.55 atm, we can use Dalton's law of partial pressures. This law states that the partial pressure of a gas in a mixture is proportional to its percentage concentration in the mixture. At sea level, dry air contains approximately 20.9% oxygen. Therefore, the partial pressure of oxygen can be calculated using the following formula:
Po₂ = (Total atmospheric pressure) × (Fraction of O₂ in air)
Given the total atmospheric pressure atop the Matterhorn is 0.55 atm, the partial pressure of O₂ is:
Po₂ = 0.55 atm × 0.209
Po₂ = 0.115 atm (Answer: d) Calculated value)
The partial pressure of oxygen decreases at high altitudes because the total atmospheric pressure (Patm) decreases, while the fraction of oxygen in the air remains constant.