Topics

FARADAY’S LAWS ( FIRST LAW & SECOND LAW)

FARADAY’S LAWS Michael Faraday (1832) made a quantitative study of the relation between the amount of electrolysis produced by the current and the quantity of electricity. His conclusions may be expressed in the form of two laws of electrolysis: FARADAY’S FIRST LAW According to this law, the mass of a substance involved in any reaction at the electrodes is directly ...

Read More »

Difference between Metallic & Electrolytic Conductors

 METALLIC & ELECTROLYTIC CONDUCTORS The passage of electric current in conductors is due to the movement of free electrons. Also the conducting material does not undergo any chemical change. A current of electricity is a stream of electrons. Examples; Metals like Cu, Al etc. Non-metals like graphite. The flow of current in conductors is due to the movement of ions ...

Read More »

Conductors & Types of Conductors

CONDUCTORS The substances which allow the electric current to pass through them are called conductors. There are two types of conductors. (i) METALLIC CONDUCTORS The passage of electric current in conductors is due to the movement of free electrons. Also the conducting material does not undergo any chemical change. A current of electricity is a stream of electrons. Examples; Metals ...

Read More »

Applications & Uses of Colloids

Applications & Uses of Colloids Colloids play an important role in our daily life. Some important applications of colloids are: (1)COLLOIDAL MEDICINES The medicines used in the form of colloids are more effective on account of their easy adsorption and assimilation. Colloidal sulphur, colloidal calcium etc. are used as medicines for different diseases. Antibiotics are mostly used in colloidal form. ...

Read More »

ELECTRICAL PROPERTIES OF COLLOIDS

ELECTRICAL PROPERTIES OF COLLOIDS Colloidal particles always carry some charge which is responsible for the stability of the sols. Certain colloidal solutions such as ferric hydroxide hydrosol are positively charged, whereas the particles of arsenious sulphide hydrosol negatively charged. The charge on the colloidal particles may be due to the following factors. (a)THE PRESENCE OF ACIDIC AND BASIC GROUPS The ...

Read More »

KINETIC PROPERTIES PROPERTIES OF COLLOIDS

KINETIC PROPERTIES PROPERTIES OF COLLOIDS   Robert Brown in 1927 observed that pollen grains when placed in a liquid and seen through a microscope show a zig-zag motion. He also found that colloidal particles present in a sot. show the same type of motion. This random zig-zag motion of the colloidal particles is known as Brownian movement. This movement is ...

Read More »

OPTICAL PROPERTIES OF COLLOIDS

OPTICAL PROPERTIES OF COLLOIDS The colloidal solution shows the property of scattering of light. When light is passed though a colloidal solution, the rays are scattered. This phenomenon of scattering of light by colloidal particles present in the sols was first studied by Tyndall and is known as the Tyndall effect. The bright cone of scattered light is called Tyndall cone. When ...

Read More »

PHYSICAL PROPERTIES OF COLLOIDS

PHYSICAL PROPERTIES OF COLLOIDS  (i) COLOUR Colloidal solutions are invariably coloured.The colour of the sol depends on the wave-length of the light scattered by the dispersed particles. The wavelenght of scattered light depends on the size and shape of  colloidal particles. Thus sulphur sol with different particle size, shows different colours either bright yellow or pale yellow. (ii) HETEROGENEITY A colloidal solution ...

Read More »

Purification of Colloidal Solution -Purification of Sol

Purification of Colloidal Solution -Purification of Sol A sol prepared by any one of the above methods very often contains other material besides the colloidal particles. It is necessary to remove these impurities as they reduce the stability of the sols. The purification of sols can be done by means of the following three methods (i) Dialysis (ii) Electro dialysis ...

Read More »

PREPARATION OF COLLOIDAL SOLUTIONS

PREPARATION OF COLLOIDAL SOLUTIONS There are two ways in which colloidal size particles can be obtained (a) by building up the particles from single molecules. The methods under this category are known as condensation or aggregation methods. (b) by disintegrating  down the bulk material to the colloidal particles. Methods under this category known as the dispersion methods. In preparing a ...

Read More »

© Copyrights 2014. All rights are reserved www.latestcontents.com