Answer:
Explanation:
We are given the amounts of two reactants, so this is a limiting reactant problem.
1. Data:
We know we will need an equation with masses and molar masses, so let’s gather all the information in one place.
M_r: 65.38
Zn + 2HCl ⟶ ZnCl₂ + H₂
m/g: 12.7
V/mL: 5.00×10²
c/mol·L⁻¹: 1.450
2. Moles of each reactant
(a) Moles of Zn
(b) Moles of HCl
V = 5.0× 10² mL = 0.5000 L
3. Identify the limiting reactant
Calculate the moles of ZnCl₂ obtained from each reactant
(i) From Zn
The molar ratio is 1 mol ZnCl₂:1 mol Zn
(ii) From HCl
The molar ratio is 1 mol ZnCl₂:2 mol HCl
Zinc is the limiting reactant, because it produces fewer moles of ZnCl₂.
4. Moles of HCl reacted
The molar ratio is 2 mol HCl:1 mol Zn
5. Moles of HCl remaining
n = 0.7250 - 0.3885 = 0.3365 mol HCl
6. Concentration of hydrogen ions
The HCl is completely dissociated.