- #1
EmilyHopkins
- 8
- 0
Calculate the standard enthalpy of ethyne
C2H2 + 2H2 -------> C2H6
Assume the following mean bond energies
C[itex]\equiv[/itex]C = 813 KJ mole-1
C - C = 364 KJ mole-1
C - H = 413 KJ mole -1
H - H = 436 KJ mole -1
Attempted Solution:
Bonds broken
1 C[itex]\equiv[/itex]C = 813 KJ mole-1 ( 813 KJ mole-1)
2 H - H = 436 KJ mole -1 (2 x 436 KJ mole -1)
Bonds formed
4 C - H = 413 KJ mole -1 (4x 413 KJ mole-1)
1 C - C = 364 KJ mole-1 (364 KJ mole-1)
ΔHh - Enthalpy of hydrogenation
ΔHh = ((813 + 2x 436) - ((4x 413) + 364)) KJ mole -1
ΔHh = 1685 KJ mole-1 - 2016 KJ mole-1
ΔHh = -331 KJ mole -1
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Is my method and the way I worked it out correct ?
C2H2 + 2H2 -------> C2H6
Assume the following mean bond energies
C[itex]\equiv[/itex]C = 813 KJ mole-1
C - C = 364 KJ mole-1
C - H = 413 KJ mole -1
H - H = 436 KJ mole -1
Attempted Solution:
Bonds broken
1 C[itex]\equiv[/itex]C = 813 KJ mole-1 ( 813 KJ mole-1)
2 H - H = 436 KJ mole -1 (2 x 436 KJ mole -1)
Bonds formed
4 C - H = 413 KJ mole -1 (4x 413 KJ mole-1)
1 C - C = 364 KJ mole-1 (364 KJ mole-1)
ΔHh - Enthalpy of hydrogenation
ΔHh = ((813 + 2x 436) - ((4x 413) + 364)) KJ mole -1
ΔHh = 1685 KJ mole-1 - 2016 KJ mole-1
ΔHh = -331 KJ mole -1
--
Is my method and the way I worked it out correct ?