It is possible to investigate the thermo chemical properties of hydrocarbons with molecular modeling methods.
(a) Use electronic structure software to predict ∆cHo values for the alkane’s methane through pentane. To calculate ∆cHo values, estimate the standard enthalpy of formation of CnH2 (n+l) (g) by performing semi-empirical calculations (for example, AMI or PM3 methods) and use experimental standard enthalpy of formation values for CO2 (g) and H20 (I).
(b) Compare your estimated values with the experimental values of ∆cHo (Table 2.5) and comment on the reliability of the molecular modeling method.
(c) Test the extent to which the relation ∆cHo= k {(M/ (g mol-1)} n holds and find the numerical values for k and n.