Task 2.1f.2

1. Calculate the enthalpy change for the reaction:  (answer = -137kJmol^-1)
C₂H_4(g)(g) + H_2(g) ---> C₂H_6(g)
given the following standard enthalpies of combustion:
DH^o_c (C₂H_4(g)) = - 1411Jmol^-1
DH^o_c(H_2(g))      =  - 286kJmol^-1
DH^o_c (C₂H_6(g)) =  - 1560kJmol^-1

2. Calculate the standard enthalpy change of formation of methane from the following enthalpies of combustion. (answer = -76kJmol^-1)
DH^o_c (CH_4(g))   = - 890Jmol^-1
DH^o_c(H_2(g))      =  - 286kJmol^-1
DH^o_c (C_(s))       =  - 394kJmol^-1

3. Calculate the standard enthalpy of formation of ethanol, C₂H₅OH, from the following standard enthalpies of combustion:
DH^o_c (C₂H₅OH_(l))   = - 1367Jmol^-1
DH^o_c(H_2(g))            =  - 286kJmol^-1
DH^o_c (C_(s))             =  - 394kJmol^-1

4. Methanol can be made in a two-step process.
Step 1:  CH₄(g) +H₂O(g) == CO(g) + 3H₂(g)
Step 2:  CO(g) + 2H₂(g) == CH₃OH(g)
Use the following enthalpies of combustion to calculate the enthalpies of reaction for each of the steps:
DH^o_c (CH_4(g))   = - 890mol^-1
DH^o_c(H_2(g))      =  - 245kJmol^-1
DH^o_c (CO_(g))       =  - 283kJmol^-1
DH^o_c (CH₃OH_(g))   = - 671Jmol^-1