Colloidal State
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COLLOIDAL STATE A colloidal state of matter is a state in which the size of the particles in such (10A-1000A) that they can pass through filter paper but not through animal or vegetable membrane. Sr. No. Property True solutions Colloidal solutions Suspensio ns 1 Particle size Less than 10-9m or 1 nm Between 10-9 to 10-7mm or 1 nm to 100 nm More than 10-7 m or 100 nm 2 Filterabil ity Pas through ordinary filter paper as well as animal membrane pass through ordinary filter paper but not through animal membrane Do not pass through filter paper and animal membrane 3 Settling Do not settle Do not settle Settle on standing 4 Visibility Particles are in visible Scatterin g of light by the particle
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Colloidal State
Transcript of Colloidal State
COLLOIDAL STATE
A colloidal state of matter is a state in which the size of the particles in such (10A-1000A) that they can pass through filter paper but not through animal or vegetable membrane.
Sr. No. Property True solutions Colloidal solutions
Suspensions
1 Particle size Less than 10-9m or 1 nm
Between 10-9 to 10-7mm or 1 nm to 100 nm
More than 10-7 m or 100 nm
2 Filterability Pas through ordinary filter paper as well as animal membrane
pass through ordinary filter paper but not through animal membrane
Do not pass through filter paper and animal membrane
3 Settling Do not settle Do not settle Settle on standing
4 Visibility Particles are in visible
Scattering of light by the particle is overved under ultramiorscope
5 Diffuse quickly Diffuse slowly Do not diffuse 6 Appearance Clear and
transparent Translucent Opaque
Classification of colloids or colloidal solution.
The various substance which form colloidal solution are divided into two categories:
Lyophilic and Lyopnobic.
1. Lyophilic Colloids:
The ward lyophilic means liquid loving. Substance like gum, gelative, starch, rubber etc. which when mixed with a suitable liquid as the dispassion medium directly form the colloidal sol. are called lyophilic and thus obtained are called by lyophilic solution.
2. Lyophobic colloids
The word ‘lyophobic’ means liquid hating. Substances like metals, their sulphides etc. when simply mixed with the dispersion medium do not form the colloidal solution. Their colloidal solution can be prepared only by special methods. Such substances are called lyophobic and the sols formed by them are called lyophobis sols.
The greater stability of the lyophilic solution then the lyophobic sols is due to the fact that the former are highly hydrated in the solution.
Multimolecular, Macro-Molecular and Associated colloids
(i) Multimolecular colloids
When on dissclution a large number of atoms or smaller molecules of a substance aggregate together to form species having size in the colloidal range, the species thus formed are called multimolecular colloids.
