KEY PART that is TRICKY for me: (The vapor pressure of water is23.78 mmHg at 25∘C)
A common way to make hydrogen gas in the laboratory is to placea metal such as zinc in hydrochloric acid (see the figure). Thehydrochloric acid reacts with the metal to produce hydrogen gas,which is then collected over water. Suppose a student carries outthis reaction and collects a total of 154.0 mL of gas at a pressureof 742 mmHg and a temperature of 25∘C. What mass of hydrogen gas(in mg) does the student collect? (The vapor pressure of water is23.78 mmHg at 25∘C.)
Can someone please help me with this problem, because I amlosing my mind. I thought the answer was going to be either 12.3 mgor 12.4 mg, but that's without factoring in the vapor pressure ofwater, and I do not know what to do with that information. Pleasehelp. Thank you.
