Chlorine is prepared in the laboratory by treating manganese dioxide (MnO₂) with aqueous hydrochloric acid according to the reaction



How many grams of HCl react with 5.0 g of manganese dioxide?

Given:

Mass of Manganese Dioxide = 5 g

Atomic Mass of Manganese = 55g

Atomic Mass of Oxygen = 16g

Atomic Mass of Hydrogen = 1g

Molecular Mass of MnO₂ = 55 + [16×2]

= 55 + 32

= 87g

Molecular Mass of HCl = 1 + 35.5

= 36.5g

So by observing the chemical reaction we see that,

1moles of MnO₂ reacts with 4moles of HCl

87g of MnO₂→ 4×36.5g of HCl

So 5g of MnO₂→ X g of HCl

X = [146×5]/87

X = 730/87

X = 8.39g

So, 8.4g of HCl will react completely with 5g of MnO₂.