Question

Determine how many moles of O2 are required to react completely with 6.5 moles C6H14.

Answer 1

Answer: 62 moles of $O_2$

Explanation:

Combustion is a type of chemical reaction in which a substance is reacted with oxygen to form carbon dioxide and water.

The balanced chemical reaction for combustion of $C_6H_{14}$

$2C_6H_{14}+19O_2 \rightarrow 12CO_2+14H_2O$

From the stoichiometry:

2 moles of hexane react with = 19 moles of oxygen

Thus 6.5 moles of hexane react with = $\frac{19}{2}\times 6.5=62$ moles of oxygen

Thus 62 moles of $O_2$ are required to react completely with 6.5 moles of $C_6H_{14}$.

Answer 2

Ou need a balanced equation. When butane burns it produces CO2 and H2O so C4H10 + 13/2 O2 ------------------> 4 CO2 + 5 H2O It is easier however, to use whole numbers when trying to work this problem out so multiply everything by 2 2C4H10 + 13 O2 -------------------> 8 CO2 + 10 H2O Now you are told you have 4.9 moles of C4H10 The equation says that for every 2 moles of C4H10 you burn you also burn 13 moles of O2 So the mole ratio is 2 to 13 OR 13/2 or you need 6.5 times as many moles of O2 as you have of C4H10. Therefore if you start with 4.9 mol of C4H10, you will need 4.9 mol x 6.5 or 31.85 mol of O2