Question

Magnesium oxidizes via the reaction: 2 Mg + O2 → 2 MgO The reaction has a △Hrxn = -1203 kJ. How much heat (in kJ) is released when you completely react 3.000 moles of O2?

Answer 1

Answer : The amount of heat released is, -3609 KJ

Solution : Given,

Enthalpy of reaction,
`\Delta H_(rxn)` = -1230 KJ

Moles of
`O_2` = 3 moles

The given balanced reaction is,

`Mg+O_2\rightarrow 2MgO`

From the balanced reaction we conclude that

1 mole of
`O_2` releases heat = -1230 KJ

3 moles of
`O_2` releases heat =
`(3moles)/(1mole)* -1230KJ=-3609KJ`

Therefore, the amount of heat released is, -3609 KJ