There are only 0.25 moles of HCl (instead of 0.3 moles), so the HCl will run out first. It is the limiting reactant. Now use the moles of the limiting reactant to calculate the mass of the product.

The equation shows that 1 mol of HCl reacts with 1 mol of NaOH. So the amount of NaOH in 20.0 cm 3 is 0.025 mol. Substituting into the equation to find the concentration of NaOH: \(Concentration ...