Question

How many grams of HCl(aq) are required to react completely with 1.25g of Zn(s) to form ZnCl2(aq) and H2

Answer 1

1.39 g HCl

Explanation:

The balanced chemical equation for this reaction is given by

Zn(s) + 2HCl(aq) ---> ZnCl2(aq) + H2(g)

Convert the # of grams of Zn to moles:

1.25 g Zn × (1 mol Zn/65.38 g Zn) = 0.0191 mol Zn

Use the molar ratio to find the # of moles of HCl needed to react completely with the given amount of Zn:

0.0191 mol Zn × (2 mol HCl/1 mol Zn) = 0.0382 mol HCl

Convert this amount to grams:

0.0382 mol HCl × (36.458 g HCl/1 mol HCl) = 1.39 g HCl