after starting with 0.343g Al and excess HCl the volume of H2 gas collected over water was 472ml. the atmospheric pressure was 754 mmHg and the temp was 21c.

Question

after starting with 0.343g Al and excess HCl the volume of H2 gas collected over water was 472ml. the atmospheric pressure was 754 mmHg and the temp was 21c.
1 balanced chemical equation?
2calculate the pressure in atm of dry hydrogen gas in a mixture

DrBob222 · Answer

Ptotal = pH2 + pH2O
Ptotal = 754 mm
pH2O = look up the vapor pressure of H2O at 21 C. One web site shows that as 18.7 mm
So 754-18.7 = pH2 which is pressure of the DRY hydrogen gas. Then convert that to atm.