How many liters of hydrogen gas are needed to generate 90.0g of water 25C and 1atm pressure?
What are the conversions I need?
Write the balanced equation.
2H2 + O2 --> 2H2O
Convert 90 g H2O to mols, convert that to mols H2 using the coefficients in the balanced equation (its 1:1 so it makes it easy), then use that as n in PV=nRT to determine volume.
Post your work if you need further assistance.
Use PV = nRT to calculate