34. Which of the following liquids has the least density ? A.Fresh water B.Salt water C.Petrol D.Mercury
Option C Solution: Gasoline or petrol is a transparent, petroleum derived liquid that is used primarily as a fuel in internal combustion engines. It consists mostly of organic compounds obtained by the fractional distillation of petroleum, enhanced with a variety of additives. The specific gravity (or relative density) of gasoline ranges from 0.71–0.77 kg/l (719.7 kg/m3 ; 0.026 lb/m3; 6.073 lb/US gal; 7.29 lb/imp gal), higher densities having a greater volume of aromatics. Gasoline floats on water; water cannot generally be used to extinguish a gasoline fire, unless used in a fine mist.
