Passage :

1.         The reverse of disproportionate is comproportionation.

2.         In these reactions, two species with the same element in two different   oxidation states form a single product.

                              

Q.   $\text{2Na}+{\text{2H}}_{\text{2}}\text{O}\to \text{2NaOH}+{\text{H}}_{\text{2}}$ . This reaction is