Task 2.1f.1

1. Calculate the enthalpy change of combustion of ethene, C₂H₄, given the following standard enthalpy changes: (answer = - 1412kJmol^-1)
DH^o_f (C₂H_4(g)) = + 52kJmol^-1
DH^o_f (CO_2(g)) =  -394kJmol^-1
DH^o_f (H₂O_(l)) =  - 286kJmol^-1

2. Calculate the enthalpy change for the reaction: (answer = +178kJmol^-1)
CaCO_3(s) ---> CaO_(s) + CO_2(g)
Standard enthalpies of formation:
DH^o_f (CaCO_3(s)) = - 1207kJmol^-1
DH^o_f (CaO_(s)) =      - 635kJmol^-1
DH^o_f (CO_2(g)) =     - 394kJmol^-1

3. Calculate the standard enthalpy of formation of solid ammonium chloride, NH4Cl, using the following data:  (answer = -508kJmol^-1)
DH^o_f (NH_3(g)) =  - 46.1kJmol^-1
DH^o_f (HCl_(g)) =  - 286kJmol^-1
NH_3(g) + HCl_(g)  --->  NH₄Cl_(s)        DH^o =  - 176kJmol^-1

4. Calculate the standard enthalpy change of the reaction: (answer = -3312Jmol^-1)
4FeS2(s) + 11O2(g)  ---> 2Fe2O3(s) + 8SO2(g)
Standard enthalpy changes of formation in kJmol-1:
DH^o_f (FeS_2(s)) =  - 178kJmol^-1
DH^o_f (Fe₂O_3(s)) =  - 824kJmol^-1
DH^o_f (SO_2(g)) =  - 297kJmol^-1