Question

drop a crystal of copper sulphate on potassium permanganate into a glass of hot water and another containing cold water. do not stay the solution. allow the crystals to settle at the bottom.
what do you observe just above the solid crystal in the glass?
what happens as time passes?
what does this suggest about the particles of solid and liquid?
does the rate of mixing change with temperature?why and how?

Answer 1

Hey lakshya..

When crystals of copper sulphate are added to a glass of hot water and cold water and the solutions are not stirred, we observe that

1) In the glass of cold water, copper sulphate settles at the bottom but in the glass of hot water it slowly spreads. The copper sulphate crystals can be seen dissolving in the glass of hot water as the water just above the crystals will become blue in colour.

2) After some time, copper sulphate will dissolve in the glass of hot water and the a blue-coloured solution will be obtained. It will also dissolve in cold water, but in very small amount and there will be no appreciable change in the colour of solution.

3) This tells us that particles of matter are continuously moving that is they possess kinetic energy. As the temperature rises, particles move faster. In other word, their kinetic energy increases with increase in temperature. Thus mixing changes with temperature.

4) Also the particles of matter intermix on their own with each other, by getting into spaces between each other. This intermixing of particles of two different types of matter on their own is called diffusion.

#hope helped