If you weighed out 0.38 grams of calcium and reacted it with excess amount of HCI how many miles of H2 grams would you expect to produce?

Answer 1

I assume you meant moles and not miles.
Ca + 2HCl ==> CaCl2 + H2
mols Ca = grams/atomic mass = ?
mols H2 = mols H2 (look at the equation. 1 mol Ca produces 1 mol H2)

Answer 2

4.008