How many mL of a 3.2M NaOH solution is required to neutralize 74mL of a 12.4M HCl solution?

1 Answer
May 5, 2016

Approx. 300 mL

Explanation:

For all these sorts of problems we require a balanced chemical equation:

NaOH(aq) + HCl(aq) rarr NaOH(aq) + H_2O(l)

Such a scheme establishes that there is a 1:1 equivalence between moles acid and moles of base.

"Moles of hydrochloric acid" = 74xx10^-3Lxx12.4*mol*L^-1=0.895*mol.

Thus we require a quantity of 0.895*mol*"NaOH":

(0.895*cancel(mol))/(3.2*cancel(mol)*L^-1) = 0.28*L" sodium hydroxide solution"

This quantity is reasonable as the the acid is 4 times as concentrated as the base.