65 g of metallic zinc was affected by 70 grams of hydrochloric acid. Find the mass of zinc chloride formed

Given:
m (Zn) = 65 g
m (HCl) = 70 g
To find:
m (ZnCl2) =?
Decision:
1) We draw up the equation of the chemical reaction, let the mass of zinc chloride be x g.
Zn + 2HCl = ZnCl2 + H2
2) Let’s find the molecular weight of all the substances we need.
M (Zn) = 65 g / mol
M (HCl) = 1 + 35.5 = 36.5 g / mol, since 2 mol is 73 g / mol
M (ZnCl2) = 65 + (35.5 x 2) = 136 g / mol
3) Find the substance by which we will count. To do this, we find the amount of zinc and hydrogen chloride.
n (Zn) = 65: 65 = 1 mol
n (HCl) = 70: 35.5 = 1.9 mol
We calculate by deficiency, that is, by zinc.
65 g: 65 g / mol = x g: 136 g / mol
x = (65 x 136): 65 = 136 g.
Answer: m (ZnCl2) = 136 g.