12th Solid State Chem.
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Class XII: Chemistry Chapter 1: The Solid State Concept 1. Solid: Solid is a state of matter in which the constituting particles are arranged very closely. The constituent particles can be atoms, molecules or ions. Properties of solids: a. They have definite mass, volume and shape. b. Intermolecular distances are short and hence the intermolecular forces are strong. c. Their constituent particles have fixed positions and can only oscillate about their mean positions. d. They are incompressible and rigid. 3. Classification of on the basis of the arrangement of constituent particles: a. Crystalline solids: The arrangement of constituent particles is a regular orderly arrangement. Example: iron, copper, diamond, graphite b. Amorphous solids: The arrangement of constituent particles is an irregular arrangement. Example: Glass, plastics, rubber 4. Properties of crystalline solids: a. They have a definite characteristic geometrical shape b. They have a long range order. c. They have a sharp melting point. d. They are anisotropic in nature i.e. their physical properties show different values when measured along different directions in the same crystal. e. When cut with a sharp edged tool, they split into two pieces and the newly generated surfaces are plain and smooth. f. They have a definite and characteristic heat of fusion g. They are called true solids 5. Polymorphic forms or polymorphs: The different crystalline forms of a substance are known as polymorphic forms or polymorphs. For example: graphite and diamond.
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Type of Solid Molecular solids 1. Non polar 2. Polar 3. Hydrogen bonded Ionic solids Ions Dipole-dipole interactions Hydrogen bonding Coulombic or electrostatic HCl, solid SO2, solid NH3 H2O (ice) Soft Hard Insulator Insulator Low Low
Types of crystalline solids:
Constituen t Particles Molecules Bonding/ Attractive Forces Dispersion or London forces
Class XII: Chemistry Chapter 1: The Solid State Concept 1. Solid: Solid is a state of matter in which the constituting particles are arranged very closely. The constituent particles can be atoms, molecules or ions. Properties of solids: a. They have definite mass, volume and shape. b. Intermolecular distances are short and hence the intermolecular forces are strong. c. Their constituent particles have fixed positions and can only oscillate about their mean positions. d. They are incompressible and rigid. 3. Classification of on the basis of the arrangement of constituent particles: a. Crystalline solids: The arrangement of constituent particles is a regular orderly arrangement. Example: iron, copper, diamond, graphite b. Amorphous solids: The arrangement of constituent particles is an irregular arrangement. Example: Glass, plastics, rubber 4. Properties of crystalline solids: a. They have a definite characteristic geometrical shape b. They have a long range order. c. They have a sharp melting point. d. They are anisotropic in nature i.e. their physical properties show different values when measured along different directions in the same crystal. e. When cut with a sharp edged tool, they split into two pieces and the newly generated surfaces are plain and smooth. f. They have a definite and characteristic heat of fusion g. They are called true solids 5. Polymorphic forms or polymorphs: The different crystalline forms of a substance are known as polymorphic forms or polymorphs. For example: graphite and diamond.
2.
Get the Power of Visual Impact on your side Log on to www.topperlearning.com
2
6.
Type of Solid Molecular solids 1. Non polar 2. Polar 3. Hydrogen bonded Ionic solids Ions Dipole-dipole interactions Hydrogen bonding Coulombic or electrostatic HCl, solid SO2, solid NH3 H2O (ice) Soft Hard Insulator Insulator Low Low
Types of crystalline solids:
Constituen t Particles Molecules Bonding/ Attractive Forces Dispersion or London forces