Question

Type the correct answer in the box. Express the answer to three significant figures.

Answer 1

Answer : The energy released is -3319.7 KJ.

Solution : Given,

Mass of methane = 59.7 g

Molar mass of methane = 16 g/mole

$\Delta H=-890KJ/mole$

The value of $\Delta H$ is in negative that means the energy is releasing.

First we have to calculate the moles of methane.

Moles of methane = $\frac{\text{ Mass of methane}}{\text{ Molar mass of methane}}= \frac{59.7g}{16g/mole}=3.73moles$

Now we have to calculate the amount of energy released.

The given reaction is,

$CH_4+2O_2\rightarrow CO_2+2H_2O$

From the reaction, we conclude that

1 mole of methane releases -890 KJ/mole of energy

3.73 moles of methane releases $\frac{-890KJ/mole}{1mole}\times 3.73mole=-3319.7KJ$ of energy

Therefore, the energy released is -3319.7 KJ.