Question

(7.02 LC) Which statement about this reaction is correct?

Answer 1

Answer: The reaction of one mole of oxygen
`(O_2)` releases 445 kJ of energy.

Step-by-step explanation:

Exothermic reactions are defined as the reactions in which energy of the product is lesser than the energy of the reactants. The total energy is released in the form of heat and
`\Delta H` for the reaction comes out to be negative.

Endothermic reactions are defined as the reactions in which energy of the product is greater than the energy of the reactants. The total energy is absorbed in the form of heat and
`\Delta H` for the reaction comes out to be positive.

`CH_4(g)+2O_2(g)\rightarrow CO_2(g)+2H_2O(l)`
`\Delta H=-890kJ`

on halving the reaction, enthalpy also becomes half

`(1)/(2)CH_4(g)+O_2(g)\rightarrow (1)/(2)CO_2(g)+H_2O(l)`
`\Delta H=-445kJ`

Thus The reaction of one mole of oxygen
`(O_2)` releases 445 kJ of energy.