The balanced chemical equation for the reaction between hydrochloric acid HCl and sodium hydroxide NaOH is:HCl + NaOH NaCl + H2OThis is an acid-base neutralization reaction, where hydrochloric acid donates a proton H+ to sodium hydroxide, which donates a hydroxide ion OH- . The products are sodium chloride NaCl and water H2O .In a neutralization reaction, the concentration of H+ and OH- ions in the resulting solution depends on the initial concentrations of the acid and base. If the reaction goes to completion and both reactants are present in stoichiometric amounts, the resulting solution will be neutral, with a pH of 7. In this case, the concentration of H+ and OH- ions will be equal to 1 x 10^-7 M, as this is the concentration of these ions in pure water at 25C.If there is an excess of either the acid or the base, the concentration of H+ or OH- ions in the resulting solution will be different. To determine the exact concentration, you would need to know the initial concentrations of the reactants and the volume of the solution.