# When 30.0 moles of zinc reacts with excess H_3PO_4, how many grams of hydrogen are produced?

Dec 4, 2016

$30$ $\text{g}$
$3 {\text{Zn" + 2"H"_3"PO"_4 -> "Zn"_3("PO"_4)_2 + 3"H}}_{2}$
The molar ratio of zinc: hydrogen is $3 : 3$ so moles of zinc = moles of hydrogen.
$\text{m"="nM} = 30 \times 1 = 30$ $\text{g}$