What is the chemical reaction that occurs when a century egg is made using NaOH and NaCl? Why does the chemical reaction [math]\require{mhchem}\ce{H2O + NaCl -> H+ + Cl- + OH- + Na+}[/math] happen instead of [math]\ce{H2O + NaCl -> HCl + NaOH}[/math] in every day life?