p,v, T -data of the pure vapour phase including five concentrations (y) 19.94, 39.72, 61.07, 77.04, and 98.92 Mol-% H 2 SO 4 , a density range (1/ v ) from 1.1 to 38.3 g/1, pressures ( p ) up to about 50 bar, temperatures ( T ) up to 823 K, have been determined ...