Vol. of Hydrogen displaced at NTP is defined as the volume of hydrogen that is displaced by the equivalent mass of a metal at NTP from an acid, alkali, or alcohol. And is denoted by VE.M. Vol. of Hydrogen displaced at NTP is usually measured using the Milliliter for Volume. Note that the value of Vol. of Hydrogen displaced at NTP is always negative. Typically, the value of Vol. of Hydrogen displaced at NTP lies in the range from 11199 to 11201.