Question

What is the coefficient of oxygen gas after balancing the following equation, `P(s) + O_2 -> P_2O_5(s)`?

Answer 1

`5/2?` Of course the `P` coefficient has to be changed as well.

Explanation:

Of course, if you like, you can make a meal of the the equation:

`P_4(s) + 5O_2(g) rarr P_4O_10(s)`

The stoichiometry, the grams of reactant required for the grams of product, is precisely the same in each equation.