Question

Calcium hydroxide, used to neutralize acid spills, reacts with hydrochloric acid according to the following equation: Ca(OH)2 + 2HCl → CaCl2 + 2H2O

If you have spilled 6.3 mol of HCl and put 2.8 mol of Ca(OH)2 on it, which substance is the limiting reactant?

Answer 1

Balanced Reaction:

Ca(OH)2 + 2HCl → CaCl2 + 2H2O

As per the balanced reaction, 2 moles of HCl reacts with one mole of Ca(OH)2

So, 2.8 moles of Ca(OH)2 will react and neutralize 2 * 2.8 or 5.6 moles of HCl.

So, moles of HCl left = 6.3 - 5.6 = 0.7

Hence, Ca(OH)2 is the limiting reagent in the reaction

Note - Post any doubts/queries in comments section. Rate the answer positive if found helpful.