Mass of reactants in a chemical equation 0001

, por F_y_Q

How many grams of O_2 are needed to react with 120 g of NO, in order to obtain NO_2?


The chemical equation is:

2NO + O_2\ \to\ 2NO_2

The molecular mass of NO is equal to (14 + 16) = 30 g/mol. Oxygen has a molecular mass of (16·2) = 32 g/mol. As you can see in the previous equation: 2·30 = 60 g of NO will need to 32 g of O_2 in order to complete the reaction. Let's go to do a mathematical proportion:

120\ g\ NO\cdot \frac{32\ g\ O_2}{60\ g\ NO} = \bf 64\ g\ O_2