Mass of Substance = Volume of Substance x Density of Substance
Density of terpinene = 847.38 kg/m3
Density of terpinene in kilogram/gallon(UK) = 0.024076688078774736
Mass of a Substance = 0.024076688078774736 x 0
0 gallon(UK) of terpinene weighs 0.0 kilogram