calculate the percentage of water vapor in a sample of air that has a partial pressure of water of 0.80 torr and a total pressure of air of 735 torr. calculate the percentage of water vapor in a sample of air that has a partial pressure of water of 0.80 torr and a total pressure of air of 735 torr. 0.11 % 9.2 × 10-4 % 1.1 % 0.92 % 1.1 × 10-2 % 0.11 %