Railway Science (Chemistry-Ideal Gas Law)

A balanced equation of methane - CH₄ (Methane) + 2O₂ (Oxygen) → CO₂ (Carbon dioxide) + 2H₂O (Water) . This shows Combustion of one methane gas molecule gives 1 carbon dioxide and 2 water molecules, respectively.

The freezing point is the temperature at which a liquid freezes. Water (H2O) is an inorganic, transparent, tasteless and odorless substance. The boiling point of water is 100 ºC.
Thus required temperature conversion formulas are K (Kelvin) = C (centigrade) + 273.15 and C = {F (Fahrenheit) − 32} × 5⁄9. The Kelvin scale is named after William Thomson, also known as Lord Kelvin.

It is used in the preparation of soda water by the process of carbonation (a process that causes the water to become effervescent). The amount of carbon dioxide that can be dissolved in water is described by Henry's Law.
All aerated drinks like Pepsi, Coke, etc contain Carbon dioxide. It is a colorless and odorless gas. pH level : 3 - 4. Freon gas is used as a refrigerant. Nitrogen (N) is non metal and comprises about 78% of the atmosphere.

Evaporation - It is a type of vapourization of liquid into gaseous form. Decantation - It is the process of separation of liquid from solid and other immiscible (non-mixing) liquids. Filtration - It is a physical or chemical separation process that separates solid matter and fluid from a mixture.

An especially notable irregular maximum density is that of water, which reaches a density peak at 4 °C (39 °F, 277K) because at this temperature two opposing effects are in balance. This property has an important environmental effect (Bodies of water, such as lakes and ponds, freeze at the top first).

Chlorine - A toxic, corrosive, greenish-yellow gas that is irritating to the eyes and to the respiratory system. It is the second-lightest of the halogens. Carbon monoxide - An odorless, colorless gas formed by the incomplete combustion of fuels.
Iodine (The heaviest of the stable halogens) is a mineral found in some foods. Hydrogen sulphide (H₂S) - It is a colorless chalcogen-hydride gas, and is poisonous, corrosive, and flammable, with trace amounts in the ambient atmosphere having a characteristic foul odor of rotten eggs.

Monoatomic (The elements which exist as a single atom). Example - Noble gas : Helium (He), Neon (Ne), Argon (Ar), Krypton (Kr), Xenon (Xe).
Polyatomic - The elements which exist as groups of more than two atoms. Example - Selenium (Se), Ozone (O₃). Diatomic - The elements which exist in atomic pairs bonded to each other. Examples - Hydrogen (H), Fluorine (F) etc.

The ideal gas equation is formulated as PV = nRT. Where, P = pressure. where, V = volume, where, n = total amount of ideal gas that is measured in terms of moles, R is the universal gas constant, and where, T = temperature.

The number of units (electrons, ions, atoms, or molecules) in one mole of any substance is called Avogadro's number or Avogadro's constant. It is equal to 6.022 ×10²³ . Avogadro's law - Equal volumes of all gases at the same temperature and pressure, have the same number of molecules.

The volume of a given amount of gas is inversely proportional to its pressure when temperature is held constant (as per Boyle's law). It means that at constant temperature, the product of pressure and volume of a fixed amount of gas is constant.