Torr is the abbreviation for Torricelli, a unit of pressure equal to 101325 N/m2. On the other hand mm of Hg is also the same pressure unit defined by the pressure exerted by a mercury column, 1 mm high, with the usual density of mercury i.e. 13.5951 g/cc and standard value of g, i.e. 980.665 cm/s2. So this unit works out to be 13.5951 * 980.665 *.01 = 101324 N/m2. or i other words the same as Torr. As a result, conversion of 750 torr to mm Hg unit yields 750 mm of Hg (ans).