Hydrogen gas produced by this reaction is typically collected via water displacement, during which time the hydrogen gas becomes saturated with water vapor. If 238.4 mL of gas with a total pressure 1.27 atm was collected via water displacement at 29.4 °C, what is the partial pressure of hydrogen gas in the sample? How many grams of aluminum must have reacted to produce this quantity of hydrogen gas? The vapor pressure of water at 29.4 °C is 30.75 torr.

Answer 1

a.
Ptotal = pH2 + pH2O.
Use PV = nRT and solve for n = number of mols.

2Al + 6H^+ ==> Al^3+ + 3H2
Convert mols H2 to mols Al and to grams.

Answer 2

22
54

Answer 3

I don't agree with the 22 (22 what?) so I didn't bother with the 54; I assume is wrong also.