The specific gravity, s, is the relative density of a substance with respect to water

swater = 1,


What good is specgrav?

  1. Well, u can quickly discover the mass of a substance m = sV (rearrange the formula)
  2. It can be used for representing density in equations where the final Pressure is not required in the question

This is good if we have the s of two liquids and their volumes, we can quickly work out the specific gravity of the mixture

100ml of water and 10ml of Hg (s = 13.6) are mixed together,

find the specific gravity of the mixture.

sV / V = s = 236 / 110

•If you can do this then it is possible to quickly determine the density of a mixture of liquids!

•If s > 1 it sinks, if s < 1 it floats!