Chlorine reacts with cold dilute caustic soda to give sodium chloride, sodium hypochlorite and water.

Explanation

a) The skeleton equation is written as
`Cl_(2)+NaOHrarrNaCl +NaOCl+H_(2)O`
b) Focusing on the oxidation numbers
`overset(0)(Cl_(2))+overset(+1)(Na)overset(-2)(O)overset(+1)(H)rarroverset(+1)(Na)overset(-1)(Cl)+overset(+1)(Na)overset(-2)(O)overset(+1)(Cl)+overset(+1)(H_(2))overset(-2)(O)`
c) Locating atoms undergoing change in oxidation numbers
`overset(0)(Cl_(2))+NaOHrarrNaoverset(-1)(Cl)+NaOoverset(+1)(Cl)+H_(2)O`
d) Determining the change in oxidation numbers

e) Cris - crossing these change in the oxidation numbers
`Cl_(2)+NaOHrarr NaCl +NaOCl+H_(2)O`
f) Balancing the atoms other than hydrogen and oxygen
`Cl_(2)+2NaOHrarrNaCl +NaOCl+H_(2)O`
This is the balanced equation.