When steam is passed over red-hot iron, magnetic oxide of iron and hydrogen are obtained. 'The reaction between steam and red-hot iron is a Reversible Reaction'. What is meant by this statement.

The reaction between steam and red-hot iron is as follows:

$3\text{Fe} + \underset{\text{steam}}{4\text{H}$2\text{O}} \rightleftharpoons \text{Fe}3\text{O}4 + 4\text{H}2

It is a reversible reaction because oxide of iron and hydrogen recombine to form iron and steam.