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2011-01-11 5:13 am

Give standard enthalpy change of formation of C2H4(g) = +52.3 kJ mol^-1
standard enthalpy change of combustion of C2H6(g) = -84.6 kJ mol^-1
standard enthalpy change of formation of CO2(g) = -394.0 kJ mol^-1
standard enthalpy change of formation of H2O(g) = -286.0 kJ mol^-1

(a) Construct an enthalpy change cycle to determine the standard enthalpy change of combustion of C2H4(g).
The answer is -1412 kJ mol^-1

(b) Construct an enthalpy change cycle to determine the standard enthalpy change for the following reaction:
C2H4(g) + H2(g) --> C2H6(g)

Explain part (b)

回答 (1)

Chem is try

2011-01-11 6:49 am

✔ 最佳答案

C2H4(g) + 3O2(g) à 2CO2(g) + 2H2O(l) -1412 kJmol-1H2(g) + 1/2O2(g) à H2O(l) -286 kJmol-1+) 3H2O(l) + 2CO2(g) à C2H6(g) + 7/2O2(g) +84.6 kJmol-1è C2H4(g) + H2(g) à C2H6(g)

圖片參考：http://imgcld.yimg.com/8/n/HA04717316/o/701101100122513873439070.jpg

2011-01-10 22:50:37 補充：
the standard enthalpy change for the following reaction:
C2H4(g) + H2(g) --> C2H6(g)

delta H = -1613.4 kJmol^-1

參考: My chemical knowledge

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