Question

what happens when chlorine react with cold dilute and hot concentrate NaOH solution?​

Answer 1

Chlorine react with sodium hydroxide to produce sodium chlorate, sodium chloride and water. The reaction takes place in a concentrated solution heating the reaction mixture. The reaction between chlorine and cold dilute sodium hydroxide solution is: NaClO3 is sodium chlorate(I).

Answer 2

The reaction takes place in a concentrated solution heating the reaction mixture. The reaction between chlorine and cold dilute sodium hydroxide solution is: NaClO3 is sodium chlorate(I).

Chlorine react with sodium hydroxideto produce sodium chlorate, sodium chloride and water. 
Cl2 + 2 NaOH ==> NaCl + NaOCl3+ H2O