Chemistry Quiz 3

Alum stops bleeding in minor cuts because of coagulation. When alum is added to water, it reacts with the water and results in positively charged ions (Al³⁺). On applying alum on fresh minor cuts, coagulation of negatively charged particles with Al³⁺ ions takes place and bleeding stops.

Phosphorus is used in making smoke bombs. White phosphorus burns with a brilliant yellow flame while producing ample amounts of white smoke which is phosphorus pentoxide (P₄O₁₀).

The process of improving the quality of rubber by heating it with sulphur is called Vulcanization. It is the process of converting natural rubber to more strong and more elastic form.

Hydrogen peroxide is an antiseptic frequently used to clean minor cuts or disinfect surfaces. Gargling with hydrogen peroxide may help treat minor mouth irritations, such as cuts or canker sores because it is an antiseptic. In fact, many types of toothpaste and mouthwash in stores already contain this compound.

Vulcanization of rubber is carried out by adding Sulphur. It is a process of improvement of the rubber elasticity and strength by heating it in the presence of sulphur, which results in three-dimensional cross-linking of the chain rubber molecules (polyisoprene) bonded to each other by sulphur atoms.

A parachute is usually made of a light, strong fabric. Terylene - A type of polyester fabric that is now being used as a material for parachutes as it is very strong and heat resistant.

Natural radioactivity was discovered by Antoine Henri Becquerel. Henri Becquerel (1852-1908) was a French physicist who discovered radioactivity through his investigations of uranium and other substances. In 1903 he shared the Nobel Prize for Physics with Pierre and Marie Curie.

Acetic acid (CH₃COOH) is the chemical name of vinegar. A dilute solution of acetic acid produced by fermentation and oxidation of natural carbohydrates is called vinegar; a salt, ester, or acylal of acetic acid is called acetate.

The mercury and sodium street lamps light up because of atomic emission. An electric discharge takes place when electricity is passed through sodium vapors at low or high pressure. As a result, the valence electron present in sodium atoms becomes excited and emits light. The mercury vapor lamp works by creating an electric current to mercury vapor within a sealed glass jacket.

Vinegar made by fermentation from cane sugar contains acetic acid. Vinegar is an aqueous solution of acetic acid and trace compounds that may include flavorings. It typically contains 5–8% acetic acid by volume. Usually, the acetic acid is produced by a double fermentation, converting simple sugars to ethanol using yeast, and ethanol to acetic acid by acetic acid bacteria.