Answer:
The answer is -2812 kJ.
Explanation:
I got this answer from another person:
The following values will vary depending on the source;
C-C 347 kJ/mole; C-H 414 kJ/mole; O-H 464 kJ/mole ; O=O 498 kJ/mole
It takes energy to break bonds and energy is released when bonds are formed.
Ethane has 1 C-C bond ; 1(347 ) 347 kJ/mole
Ethane has 6-C-H bonds; 6(414) = 2484 kJ/mole
Break the bonds of 1 mole of C2H6 = 2831 kJ
2 moles of ethane in balanced equation: 2(2831 kJ) = 5662 kJ
Break 7 O=O bonds = 7(498 ) = 3486
Total energy to break all bonds: 5662 + 2486 = +9148 kJ
2C=O bond formed in CO2 = 2(799) = 1598 kJ/mole
4 moles of CO2 = 4(1598) = 6392
2(O-H) bonds in H2O = 2(464) = 928 kJ/mole
6 moles of H2O = 6(928 kJ) = 5568
Total energy released = 6392 + 5568 = 11,960 kJ
The sign of this energy is -11,960 since it is exothermic.
Energy change for 2 moles of ethane = -11,960 + 9148 = -2812 kJ
ΔHrxn = -2812 kJ
