Question

What volume of hydrogen at STP would be produced by the action of excess dilute sulfuric acid in 40.0g of Zn?

Answer 1

First, we need to state the chemical equation:

$Zn\text{ + H2SO4 -> }ZnSO4\text{ + H2}$

The moles of 40.0g Zn are 0.62 moles Zn.

In the equation we can note that 1 mole of Zn produce 1 mole of Hydrogen.

The volume at STP is 22.4 L:

$\frac{22.4L\cdot1\text{mol H2}}{65\text{ g Zn}}\cdot40.0g\text{ Zn=13.78 L H2}$