The combustion of propane may be described by the chemical equation C 3 H 8 ( g ) + 5 O 2 ( g ) ⟶ 3 CO 2 ( g ) + 4 H 2 O ( g ) How many grams of O 2 ( g ) are needed to completely burn 91.6 g C 3 H 8 ( g ) ?

Answer : The mass of  needed are, 332.8 grams

Solution : Given,

Mass of = 91.6 g

Molar mass of = 44 g/mole

Molar mass of = 32 g/mole

First we have to calculate the moles of .

Now we have to calculate the moles of

The balanced chemical reaction is,

From the reaction, we conclude that

As, 1 mole of react with 5 mole of

So, 2.08 moles of react with moles of

Now we have to calculate the mass of

Thus, the mass of  needed are, 332.8 grams