Submitted by Editor
Study of Diffusion of solids in liquids
When substances are brought in contact with each other they intermix, this property is known as Diffusion. This property of diffusion takes place very rapidly in case of gases and to a lesser extent in case of liquids, whereas solids do not show this process of diffusion with each other. But what we can observe in case of solids is that the diffusion of solids in liquids takes place at a very slow rate.
If a solid is kept in contact with an excess of solvent in which it is soluble, some portion of the solid gets dissolved. We know that this process is known as dissolution of a solid in liquid and this process has taken place due to the diffusion of solid particles into liquid.
Molecules of solute are in constant random motion due to the collision between molecules of solute and that of the solvent.
Rate of diffusion depends upon:-
Temperature: As temperature increases, the kinetic energy of the particles increases so the speed of particles also increases which thus increases the rate of diffusion.
Size of the particle: As the size of particle
increases, rate of diffusion decreases.
Mass of the particle: As the mass of the particle increases the rate of diffusion decreases.
To study diffusion when copper sulphate is brought in contact with water (liquid)
Copper sulphate crystals, 100ml beaker.
When solids such as copper sulphate, potassium permanganate are brought in contact with liquids such as water, intermixing of substances, i.e. diffusion takes place.
To study the effect of temperature on the rate of diffusion of solids in liquids
Copper sulphate crystals, 200ml beaker, watch glass, wire gauge, burner, tripod stand, thermometer and stop watch.
|S.No.||Temperature of water||Time Taken in Minutes|
|1.||25 0C||15 Min.|
|2.||10 0C||20 Min.|
|3.||70 0C||10 Min.|
The Rate of diffusion of copper sulphate in water is in the order of Beaker 3 > Beaker 1 > Beaker 2. Thus, the rate of diffusion varies directly with temperature.
To study the effect of size of particles on the rate of diffusion of solids in liquids
Graduated 100ml measuring cylinders, copper sulphate crystals of different sizes, stop watch
|S.No.||Crystal size||Time Taken in Minutes|
Small particles undergo diffusion more quickly than bigger particles.
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