1.9 mol HCl and 3.2 mol NaOH react according to the equation

Question

HCl + NaOH −→ NaCl + H2O .
Calculate the amount in moles of H2O
formed.
Answer in units of mol

Answer 1

This is a limiting reagent (LR) problem. You know that when amounts are given for BOTH reactants.
How much H2O could be formed from the HCl if you had all of the NaOH needed? That's 1.9 mols.
How much H2O could be formed from the NaOH if you had all of the HCl needed? That's 3.2 mols.
In LR problems the small number always wins so you will get 1.9 mols H2O and there will be NaOH left over. Why is that? After all of the HCl is used up there will be no more HCl to react with the NaOH no matter how much NaOH you started with.