How to balance the chemical equation:
NaOH (hot and conc.) + Cl2 -------> NaCl + NaClO3+H2O
Cl2 + 2 NaOH ==> NaCl + NaOCl + H2O for cold NaOH
3 Cl2 + 6 NaOH ==> 5 NaCl + NaClO3 + 3 H2O for hot NaOH
Chlorine is oxidized much more strongly with hot NaOH than cold
Cl2 starts neutral and becomes +1 in NaOCl
Cl2 starts neutral and becomes +5 in NaClO3
the heat and concentrated NaOH are stronger oxidizing agents than cold dilute NaOH