Railway Science (Chemistry-Chemistry in Everyday life)

The pH of milk is around 6. At this pH, milk soon becomes spoiled and becomes undrinkable. So it cannot be kept for a longer time. To prevent the spoilage of milk, the milkman adds a very small amount of baking soda to fresh milk.

Earthen pot or vessel has a large number of tiny pores in its walls and some of the water molecules continuously keep seeping through these pores outside the pot. Example of Evaporation - Drying clothes under the Sun, Cooling down hot tea. Condensation is the process where water vapor becomes liquid.

Evaporation - Process by which a liquid turns into a gas. Examples - Sweating, Water cycle, Drying clothes, Salt production. Sublimation - Conversion of a substance from the solid to the gaseous state without its becoming liquid.
Examples - Dry ice (Solid carbon dioxide), Iodine, Camphor, Naphthalene. Condensation - process where water vapor becomes liquid.
Examples - Morning Dew, Droplets on can and bottle, Fog in the air. Fusion - Occurs when two atoms slam together to form a heavier atom. Examples - When two hydrogen atoms fuse to form one helium atom.

Freezing Point of water is 0°C (32 °F). Boiling point is 100 °C (212 °F) at 1 atmosphere of pressure (sea level). The triple point of water - At this point, ice, water, and water vapor coexist in a stable format at 273.16 kelvin (0.01 °C) and a pressure of( 611.7 pascals). 4 °C is the temperature at which liquid water has the highest density. Absolute zero occurs at a temperature of Zero kelvin (−273.15 °C).

Liquefied Petroleum Gases (LPG) is extracted from crude oil and natural gas. LPG is composed of hydrocarbons containing three or four carbon atoms. Components of LPG are propane (C₃H₈) and butane (C₄H₁₀).

When the heavier component in a mixture settles after water is added to it, the process is called sedimentation. When the water (along with the dust) is removed, the process is called decantation. The process of conversion of water into its vapour is called evaporation.

Anodizing is when a protective oxide layer is created on a metal surface, usually aluminum, through an electrochemical process. Electroplating is the process of coating a conductive surface with a metal layer using electricity.

It will displace oxygen in the air (nitrogen doesn't react with foods or affect the flavor or texture, so they stay fresher longer). Oxygen is the main reason in the air that causes spoilage.
Nitrogen - Discovered and isolated by Daniel Rutherford in 1772. Oxygen and Chlorine - Discovered independently by Carl Wilhelm Scheele. Hydrogen - Discovered by Henry Cavendish in 1766.

It is released when baking soda (Sodium Bicarbonate, NaHCO₃) is added to cake and this makes the cake rise making them soft and spongy. Sodium bicarbonate is non flammable. Baking soda is basic in nature. Baking powder is a mixture of baking soda and edible acid like tartaric acid.

Ethanol (C₂H₅OH) - Used as an antiseptic cream or lotion for the purpose of hand sanitizer and clinical practice; An antidote to methanol poisoning; A volatile and colourless liquid with a mild odour. Methanol - CH₃OH, Acetic acid (Ethanoic acid) - CH₃COOH.