If 5.0 grams of Zinc were added to 35.0 grams of H2SO4, how many grams of hydrogen gas would be evolved?

Answer 1

This is a limiting reagent (LR) problem. I know that because amounts for BOTH reactants are given.
Zn + H2SO4 ==> H2 + ZnSO4
mols Zn = grams/molar mass
mols H2SO4 = grams/molar mass

Using the coefficients in the balanced equation, convert mols Zn to mols H2.
Do the same for mols H2SO4 to mols H2.
It is quite likely that you will obtain two different values for the mols H2 and that means one of them is wrong; the correct value in LR problems is ALWAYS the smaller value and the reagent producing that value is the LR.
Now convert mols H2 to g H2 by g = mols x molar mass.

Answer 2

Thank you so much!