Answer: To calculate the partial pressure of oxygen, we need to use Dalton’s law of partial pressures. According to this law, the total pressure of a mixture of gases is equal to the sum of the partial pressures of the individual gases in the mixture.
In this case, we know that the total pressure of the mixture is 777 torr and the vapor pressure of water at 26.4°C is 25.81 mm Hg. To calculate the partial pressure of oxygen, we need to subtract the vapor pressure of water from the total pressure:
Partial pressure of oxygen = Total pressure - Vapor pressure of water Partial pressure of oxygen = 777 torr - (25.81 mm Hg / 760 torr/mm Hg) Partial pressure of oxygen = 777 torr - 0.034 torr Partial pressure of oxygen = 776.966 torr
Therefore, the partial pressure of oxygen in the sample is 776.966 torr.