Chlorine gas can be made from the reaction of manganese dioxide with hydrochloric acid. MnO₂(s) + 4HCl(aq) $\rarr$ MnCl₂(aq) + 2H₂O(l) + Cl₂(g)
According to the above reaction, which is the limiting reagent when 28 g of MnO₂ are reacted with 42 g of HCl?

Question

Chlorine gas can be made from the reaction of manganese dioxide with hydrochloric acid. MnO₂(s) + 4HCl(aq)

\rarr

MnCl₂(aq) + 2H₂O(l) + Cl₂(g)
According to the above reaction, which is the limiting reagent when 28 g of MnO₂ are reacted with 42 g of HCl?

Quizplus · Accepted Answer

To determine the limiting reagent, we need to calculate how many moles of each reactant are present.

Moles of MnO2: 
28 g MnO2 x (1 mol MnO2/86.94 g MnO2) = 0.321 mol MnO2

Moles of HCl: 
42 g HCl x (1 mol HCl/36.46 g HCl) = 1.15 mol HCl

Now we use the stoichiometry of the balanced equation to see which reactant runs out first. According to the equation, 1 mole of MnO2 reacts with 4 moles of HCl. Therefore, the maximum number of moles of MnO2 that can react is:

0.321 mol MnO2 x (4 mol HCl/1 mol MnO2) = 1.28 mol HCl

But we have 1.15 mol of HCl available, which is less than the 1.28 mol needed. This means HCl is the limiting reagent, and MnO2 is in excess.

Therefore, the best choice is B (HCl).

Chlorine Gas Can Be Made from the Reaction of Manganese →\rarr→

Chlorine Gas Can Be Made from the Reaction of Manganese $\rarr$