Question

What mass of 60% hcl by mass is required to completely react with 0.2 mol of zn?

Answer 1

We begin by writing the equation for this reaction.

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

The mole ratio is 1 : 2

For every mole of Zn we have two moles of HCl.

Moles of Zn is 0.2 moles

Moles of HCl = 2 × 0.2 = 0.4 moles

Molar mass of HCl = 36.5g/mol

Mass of HCl = molar mass × moles of HCl

= 36.5 × 0.4 = 14.6 g

60% by mass of HCl is :

60/100 × 14.6 = 8.76 g