Answer:
1
Step-by-step explanation:
Consider the following reaction:
Phosphorus burn in the presence of air and produced diphosphorus pentoxide.
Chemical equation:
P₄ + O₂ → P₂O₅
Balanced chemical equation:
P₄ + 5O₂ → 2P₂O₅
Equation is balanced because there are four phosphorus atoms ans ten oxygen atoms in both side of equation.
Coefficient with reactant and product:
P₄ 1
O₂ 5
P₂O₅ 2
There is no coefficient written before P₄ it means only one P₄ is present.