-27.77-27.67-23.59-21.21-19.65-18.56-17.74-17.11-16.61-16.20-15.85-15.56-15.31-15.09 vaporization found in the present study, 10,700 cal./mole, gives for the heat of formation of hydrazine in the gaseous state at 298.16'K.) AH= 22,750 cal./mole. Using the value of the heat content function of hydrazine from Table V and those given for nitrogen and hydrogen by Wagman, et a1., I2 the heat of formation at the absolute zero is calculated to be: Afl= ...