Respuesta :
The statement about the following reaction "CH4 (g) + 2O2 (g) yields CO2 (g) + 2H2O(l) deltaH = -890 kJ" is correct is reacting one mole of oxygen (O2) releases 445 kJ of energy. Since by reacting with two mole of oxygen, you will get a release of energy of -890kJ so if only one mole of oxygen is to be reacted, you will get -445 kJ of energy.
Answer: reacting one mole of oxygen (O2) releases 445 kJ of energy
Explanation: Exothermic reactions are defined as the reactions in which energy is released in the form of heat and [tex]\Delta H[/tex] for the reaction comes out to be negative.
[tex]CH_4+2O_2\rightarrow CO_2+2H_2O[/tex] [tex]\Delta H=-890kJ[/tex]
According to the given balanced equation:
1 mole of methane reacts with 2 moles of oxygen and 890 kJ of energy is released.
Thus when the reaction is halved, the enthalpy also gets halved.
Thus [tex]\frac{1}{2}CH_4+O_2\rightarrow \frac{1}{2}CO_2+H_2O[/tex] [tex]\Delta H=-445kJ[/tex]
Now half mole of methane reacts with 1 mole of oxygen and 445 kJ of energy is released.