Question

The equation P + O2 → P2O5 is unbalanced. When balanced, what is the correct coefficient for O2?

Answer 1

Answer : The correct coefficient for $O_2$ is, 5

Explanation :

The given unbalanced chemical reaction is,

$P+O_2\rightarrow P_2O_5$

According to the balanced chemical reaction, the number of different atoms of elements present on the reactant side should be equal to the the product side.

The balanced chemical reaction will be,

$4P+5O_2\rightarrow 2P_2O_5$

By the stoichiometry we can say that, 4 moles of phosphorous react with 5 moles of oxygen to give 2 moles of diphosphorous pentoxide as a product.

From the balanced chemical reaction, we conclude that the correct coefficient for $O_2$ is, 5

Hence, the correct coefficient for $O_2$ is, 5

Answer 2

20P
5O(2)
->
10P(2)O(5)

O2 will have a coefficient of 5