Using an isoperibol twin-Dewar solution calorimeter, the enthalpies of
reaction of normal lead styphnate monohydrate, monobasic lead styphna
te, tribasic lead styphnate dihydrate, and pentabasic lead styphnate d
ihydrate were determined as -17.29, -61.92, -196.37 and -261.12 kJ mol
(-1), respectively, which, with various ancillary data, gave the stand
ard enthalpies of formation of -738.27, -981.70, -1995.99 and -2487.84
kJ mol(-1), respectively.