Question

With the use of Archimedes' principle, state how you will find relative density of a solid denser than water and insoluble in it. How will you modify your experiments if the solid is soluble in water? 

Answer 1

Steps:

(i) With the help of a physical balance, find the weight, W₁ of the given solid.

(ii) Immerse the solid completely in a beaker filled with water such that it does not touch the walls and bottom of beaker, and find the weight W₂ of solid in water.

Observations:

Loss in weight of solid when immersed in water = (W₁ - W₂) gf

R.D. = Weight of solid in air/Loss of weight of solid in water

R.D. = W₁/(W₁ - W₂).

If the solid is soluble in water, then instead of water, take a liquid in which the solid is insoluble and it sinks in the liquid.

Then, R.D. = (Weight of solid in air/Loss of weight of solid in liquid) x R.D. of the liquid