Niharika Rana

The positions of atoms, molecules or ions in a crystal, relative to one another in space, are designated usually by points. Such a representation is called crystal lattice (space lattice)

A unit cell of crystals is the smallest repeating unit in a crystal lattice which when repeated again and again in different directions results in the crystal of the given substance.

A plot of variation of solubility of a solute with temperature is known as a solubility curve.

Information given by solubility curves:

i. Solubility of a substance at a desired temperature.

ii. Idea about variation of solubility with temperature.

iii. Comparison of the solubility of different substances at different temperatures.

iv. Prediction of which substance will crystallize out first when a solution of two or more solutes is evaporated or cooled.

Glycerine has more inter-molecular hydrogen bonds than water for the same number of molecules of each substances. This causes more inter-molecular attraction between Glycerine molecules than Water molecules. As a result, Glycerine is more viscous than Water.

Following are the major/main postulates of kinetic theory of gases:

• Molecules: A gas is composed of tiny particles called molecules whose volume, as compared with that of gas, is negligible.
• Random Motion: The molecules of a gas are in a state of constant random motion.
• Elastic Collision: Collision between gas-molecules or gas molecules and container is perfectly elastic. There is no loss of energy.
• Pressure exerted by Gas: Pressure exerted by gas is due to the bombardment of the walls of...