Calculate the maximum mass of calcium metal that should be used in an equivalent mass determination, with a 100 ml gas measuring tube for collection. Assume 80 ml of hydrogen gas at standard conditions for the purposes of calculation.

Answer 1

80 mL x (1 mol/22,400 mL) = 0.00357 mols H2 gas.
Ca + 2H2O ==> H2 + Ca(OH)2
mols H2 gas = mols Ca.
g Ca = mols Ca x atomic mass Ca.

Answer 2

I made no correction for collection over water since that was not mentioned.