Question

How many moles of CO2 are emitted into the atmosphere when 25.6 g C8H18 is burned

Answer 1

When 25.6 g  $C_{8} H_{18}$   is burned, the moles of $CO_2$  emitted into the atmosphere is 1.80 mol

Explanation:

The molar mass of octane $C_{8} H_{18}$ is calculated as  8(12) +18(1) = 114 g/mol.

Where atomic mass of Carbon is C=12, and Hydrogen H=1.The sample contains 25.6 g of octane, Therefore

 $\frac{25.6 g}{114 g / m o l}=0.225 \mathrm{mol}$

The combustion of octane can be written as:

$2 C_{8} H_{18}+25 O_{2} \rightarrow 16 C O_{2}+18 H O_{2}$

The mole ratio can be represented as:

$C O_{2}: C_{8} H_{18}$ = 16:2 =  8:1.  

Hence, the quantity of carbon dioxide emitted is:

$\frac{8}{1} \times 0.225 \mathrm{mol}$ = 1.80 mol