187) Enthaply of carbon, hydrogen and ethyl alcohol on combsution at 25^oC are −94, −68.4 and −327 kcal⁄mol, then the formation enthalpy of ethyl alcohol will be:

188) The work of expansion for a system is 500 cal. The heat given to the system is 80 cal. The change in internal energy in the process will be:

189) The heat capacity for a bomb calorimeteris 500 J⁄^oC. In an experiment, in the combustion of 0.1 gm methane, the temperature rise was by 2^oC. What is the value of ΔE per mol?

190) For a certain reaction, the change in enthalpy and the change in entropy are 40.63 kJ⁄mol and 100 J⁄K. What is the value of ΔG at 27^oC? Also, indicate whether the reaction is possible or not.

191) The bond dissociation energies of methane and ethane are 360 kcal⁄mol and 620 kcal⁄mol respectively. The C−C bond energy in kcal⁄mol is: