Question

Which of the following liquids has the lowest density?
1. Mercury
2. Fresh water
3. Salt water
4. Petrol

Answer 1

Correct Answer - Option 4 : Petrol

The correct answer is Petrol.

• Petrol has the lowest density among the given liquids.

• 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.

• Mercury is the densest liquid at standard conditions for temperature and pressure (STP).
• Mercury is also called quicksilver.
• Lighter liquids (like water or vegetable oil) are less dense than heavier liquids (like honey or corn syrup) so they float on top of the heavier liquids.
• The density of a liquid is a measure of how heavy it is for the amount measured.
  • If you weigh equal amounts or volumes of two different liquids, the liquid that weighs more is denser.
  • If a liquid that is less dense than water is gently added to the surface of the water, it will float on the water.