A sample of oxygen is collected over water at a total pressure of 692.2 mmHg at 17°C. The vapor pressure of water at 17°C is 14.5 mmHg. The partial pressure of the O2

677.7 mmHg

Explanation:

The first empirical study on the behaviour of a mixture of gases was carried out by John Dalton. He established the effects of mixing gases at different pressures in the same vessel.

Dalton's law states that,the total pressure exerted by a mixture of gases is equal to the sum of the partial pressures of the individual gases present in the mixture of gases. When a gas is collected over water, the gas also contains some water vapour. The partial pressure of the gas will now be given as; total pressure of gas mixture - saturated vapour pressure of water (SVP) at that temperature.

Given that;

Total pressure of gas mixture = 692.2 mmHg

SVP of water at 17°C = 14.5 mmHg

Therefore, partial pressure of oxygen = 692.2-14.5

Partial pressure of oxygen = 677.7 mmHg