Railway Science (Chemistry-Miscellaneous) (Part-III)

Number of elements in Ammonium Sulphate (NH₄)₂SO₄ : Hydrogen - 4 × 2 = 8, Nitrogen - 2, Oxygen - 4 and Sulphur - 1. It is an inorganic salt. Characteristics : No smell, dissolves easily in water. Appearance : Fine white crystalline solid or hygroscopic granules. Uses : As a fertilizer, reagent, insecticide, food additive and disinfectant.

Panch Tatva - Air, Earth, Fire, Sky and Water. The ancient Indian Philosopher Acharya Kanada (Kashyap) proposed that paramanu (atom) is an indestructible particle of matter. He described the universe with six categories (Dravya, Guna, Karman, Samanya, Visesa, Samavaya).

A mole is the SI unit of measurement for the amount of substance. 1 mole = 6.022 × 1023 . 1 mole of any particle has 6.022 × 10²³ of that particle. For example: 1 mole of atom = 6.022 × 10²³ atoms, 1 mole of molecule = 6.022 × 1023 molecule. 6.022 × 10²³ is known as the Avagadro number. A mole does not depend on the atomic number, it's just a unit.

Cation is an ion (charged particles) that has a positive charge on it whereas an anion has a negative charge on it. Ammonium ion (NH₄⁺) - The cation has a charge of +1. Carbonate ion (CO₃²⁻) - The anion has a charge of -2.
Nitrate ion (NO₃⁻) - The anion has a charge of -1. Hydroxide ion (OH⁻) - The anion has a charge of -1.

A compound is a substance made up of two or more atoms of different elements chemically joined (bonded) together. Example - Carbon Dioxide (CO₂). An atom is the part of an element. Example - Hydrogen (one proton and one electron). One mole of any substance is equal to the value of Avogadro's number (6.022 × 10²³) molecules.

Solid - Rigid structure, Molecules are tightly bounded by strong intermolecular forces, have a fixed volume and shape, incompressible. The rate of diffusion in solids is very low. Example : Solid ice, sugar, rock, wood etc.
Liquid - Fixed volume but no fixed shape, have lesser densities than solids, intermolecular forces of attraction are weaker than solids. Gases - No fixed shape or volume, weak forces, rapid diffusion.

The matter in the solid state will have definite shape and volume. The particles cannot move freely. The particles in the solid state are in a continuous motion. The particles of matter are very small.
The particles of matter attract each other because of the interatomic attraction force present between them. Gases have the highest amount of inter-molecular space between the particles while solids have the least.

Avogadro's number - The number of units present in one mole of a given substance. Mole - Fundamental unit of measure of the amount of a substance. For atoms, the mass of Avogadro's number of particles is equal to their atomic mass in grams. For molecules, the mass of Avogadro's number of particles is equal to their molecular mass in grams.

Chemical energy - Energy stored in the bonds of chemical compounds, like atoms and molecules. Dry Cell - It is a device that generates electricity from the chemical reaction. The cell forces the electrons to flow from one end to the other. The flow of electrons causes the current to flow in the closed circuit.

Sodium hydroxide (NaOH) is also known as lye or soda or caustic soda. At room temperature, sodium hydroxide is a white crystalline odorless solid that absorbs moisture from the air.
It is used to manufacture Soaps, Rayon, Paper, Explosives, Dyestuffs, and Petroleum products. Sodium oxide (Na₂O) is an alkali metal oxide. Chlorine (Cl): Atomic number - 17. Sodium (Na): Atomic number - 11.