When the following chemical reaction is balanced, what number is placed before nh3? n2 + 3h2 → nh3

A chemical reaction is usually defined a reaction between two or more reactants and thereby producing one or more products out of it. This reactions are needed to be balanced on both the sides by a definite number in order to conserve the mass.

In the given condition, Nitrogen is reacting with Hydrogen in order to form ammonia (NH₃)

N₂ + 3H₂ → 2NH₃

Thus, the above reaction is balanced now by putting 2 before NH₃.