Calculate the volume of hydrogen released when 19.5 g of zinc react with an excess of hydrochloric acid.

Let’s compose the equation for the reaction of zinc with hydrochloric acid.
Zn + 2HCl = ZnCl2 + H2
It can be seen from the reaction equation that when one mole of zinc interacts with hydrochloric acid, one mole of hydrogen is released, since the molar mass of zinc is 65g, and the molar volume of hydrogen at normal conditions is 22.4 l, we get:
65 g – 22.4 L
19.5 g – X l.
X = 19.5 * 22.4: 65
X = 6.72 l.
Answer: 6.72 l.