CH4 + 2O2 = CO2 + 2H2O, Calculate the energy required to break bonds and energy required to make bonds and enthalphy change ?

To calculate the energy required to break bonds and the energy required to make bonds, we need to consider the bond energies of the bonds involved in the reaction.

Bond energies:
C-H bond energy = 413 kJ/mol
O=O bond energy = 498 kJ/mol
C=O bond energy = 799 kJ/mol
O-H bond energy = 463 kJ/mol

Breaking bonds:
In CH4:
4 C-H bonds = 4 x 413 kJ/mol = 1652 kJ/mol
In 2O2:
4 O=O bonds = 4 x 498 kJ/mol = 1992 kJ/mol

Total energy required to break bonds = 1652 kJ/mol + 1992 kJ/mol = 3644 kJ/mol

Making bonds:
In CO2:
2 C=O bonds = 2 x 799 kJ/mol = 1598 kJ/mol
In 2H2O:
4 O-H bonds = 4 x 463 kJ/mol = 1852 kJ/mol

Total energy required to make bonds = 1598 kJ/mol + 1852 kJ/mol = 3450 kJ/mol

Enthalpy change:
The enthalpy change for the reaction can be calculated as the difference between the energy required to break bonds and the energy required to make bonds:
Enthalpy change = Energy required to break bonds - Energy required to make bonds
Enthalpy change = 3644 kJ/mol - 3450 kJ/mol = 194 kJ/mol

Therefore, the energy required to break bonds is 3644 kJ/mol, the energy required to make bonds is 3450 kJ/mol, and the enthalpy change for the reaction is 194 kJ/mol.

Bond Breaking:

- Breaking 4 C-H bonds: 4 - 414 kJ/mol = 1656 kJ/mol
- Breaking 2 O-O bonds: 2 - 498 kJ/mol = 996 kJ/mol

Total Bond Breaking Energy: 2652 kJ/mol

Bond Making:

- Forming 2 C=O bonds: 2 - 799 kJ/mol = 1598 kJ/mol
- Forming 4 O-H bonds: 4 - 462 kJ/mol = 1848 kJ/mol

Total Bond Making Energy: 3446 kJ/mol

Enthalpy Change (ΔH):

ΔH = Energy required to break bonds - Energy required to make bonds
ΔH = 2652 kJ/mol - 3446 kJ/mol
ΔH = -794 kJ/mol

The negative sign indicates that the reaction is exothermic, meaning it releases heat.