The standard enthalpy of combustion of solid urea (CO (NH2)2) is -632 kl mol-1 at 298 K and its standard molar entropy is 104.60 J K-1 mol-1, Calculate the standard Gibbs energy of formation of urea at 298 K.

> b takes place in the gas phase in an isothermal tubular reactor. the feed is one mole of a per one mole of c, an inert. the entering temperature and pressure are 427°c and 10 atm, respectively. the gas constant r = 0.08206 atm · l/mol · k.