The hydrogen gas produced from a chemical reaction was collected over water at 40°C with a total pressure of 715 mmHg. (Water pressure is 55.3 mmHg at 40°C.)
a. What would be the partial pressure of the hydrogen gas collected? 
b. What is the mass of hydrogen gas collected if the total volume of gas collected is 763 mL?

• A. P = 659.63 mmHg; m = 0.052 g
• B. P = 770.36 mmHg; m = 0.052 g
• C. P = 659.63 mmHg; m = 0.026 g
• D. P = 770.36 mmHg; m = 0.026 g

Answer: (A)