Explain Tyndall effect?

Colloidal solution or sol consists of fine particles invisible to naked eyes. However, when this solution is placed against a dark background and a strong beam of light is passed through it, the light scattered by them can be observed through the ultramicroscope. The path of light can be viewed from a direction at a right angle to that of incident light. The Phenomenon of scattering of light by sol particles is called Tyndall effect. It confirms the heterogeneous nature of the colloidal solution.

What is Brownian movement ?

The Brownian movement in a colloidal system is caused by the unequal bombardment of the molecules of the dispersion medium on the colloidal particles. When more molecules strike the particles on one side, the direction of the motion of particles changes. This is only visible through ultramicroscope. In colloidal solutions, the colloidal particles are in constant zig-zag motion known as Brownian motion. This phenomenon was first observed by Sir Robert Brown in the year 1827.

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NEW SYSTEMATIC MODERN CHEMISTRY>Chapter 5 - Surface Chemistry>REVIEW EXERCISES>Q 28

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Adsorption of gases on solid surface is generally exothermic because

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Important Questions on Surface Chemistry

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NEW SYSTEMATIC MODERN CHEMISTRY>Chapter 5 - Surface Chemistry>REVIEW EXERCISES>Q 29

The diameter of colloidal particles range from

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NEW SYSTEMATIC MODERN CHEMISTRY>Chapter 5 - Surface Chemistry>REVIEW EXERCISES>Q 30

Alum is a water purifier because it :

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NEW SYSTEMATIC MODERN CHEMISTRY>Chapter 5 - Surface Chemistry>REVIEW EXERCISES>Q 31

Which of the following form micelles in aqueous solution above certain concentration ?

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NEW SYSTEMATIC MODERN CHEMISTRY>Chapter 5 - Surface Chemistry>REVIEW EXERCISES>Q 32

Which of the following is correct for lyophilic sol?

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NEW SYSTEMATIC MODERN CHEMISTRY>Chapter 5 - Surface Chemistry>REVIEW EXERCISES>Q 33

The volume of the colloidal particles

V_{c}

as compared to the volume of a solute particle in a true solution

V_{s}

could be

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NEW SYSTEMATIC MODERN CHEMISTRY>Chapter 5 - Surface Chemistry>REVIEW EXERCISES>Q 34

The dispersed phase in colloidal iron (III) hydroxide and colloidal gold is positively and negatively charged, respectively. Which of the following statement is not correct

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NEW SYSTEMATIC MODERN CHEMISTRY>Chapter 5 - Surface Chemistry>REVIEW EXERCISES>Q 35

Lyophilic sols are more stable than lyophobic sols because of the particles

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NEW SYSTEMATIC MODERN CHEMISTRY>Chapter 5 - Surface Chemistry>REVIEW EXERCISES>Q 36

A plot of