Two technicians are discussing testing coolant for proper pH. Technician A says that coolant has a pH above 7 when new and becom
es lower with use in an engine. Technician B says that OAT and HOAT coolants have a lower pH when new compared to the old green IAT coolant. Which technician is correct?
H2(g) +C2H4(g)→C2H6(g) H-H +H2C =CH2→H3C-Ch3 2C -H bonds and one C-C bond are formed while enthalpy change (dH) of the reaction, H-H: 432kJ/mol C=C: 614kJ/mol C-C: 413 kJ/mol C-C: 347 kJ/mol dH is equal to sum of the energies released during the formation of new bonds or negative sign, and sum of energies required to break old bonds or positive sign. The bond which breaks energy is positive. 432+614 =1046kJ/mol Formation of bond energy is negative 2(413) + 347 = 1173 kJ/mol dH reaction is -1173 + 1046 =-127kJ/mol
