Chemistry Quiz 6

The gas used for filling weather balloons is helium. Hydrogen is lighter than air and can be used in filling air balloons but due to its highly inflammable nature, it is not used in air balloons.

Detergents are Sodium salts of sulphonic acids. A detergent is a surfactant with cleansing properties when in dilute solutions. Detergents are the sodium salts of long-chain alkyl hydrogen sulphate or a long chain of benzene sulphonic acid.

Calcium carbide (CaC₂) reacts with water to give acetylene (IUPAC name ethyne) gas and calcium hydroxide. CaC₂+2H₂O→Ca(OH)₂+C₂H₂(acetylene)

Sir Joseph John Thomson (1856-1940) was an English physicist who helped revolutionize the knowledge of atomic structure by his discovery of the electron (1897). Electron was discovered by him when he was studying the properties of the cathode rays.

Stains of rust on clothes can be removed by oxalic acid (ethanedioic acid). Oxalic acid is widely used as an acid rinse in laundries, where it is effective in removing rust and ink stains because it converts most insoluble iron compounds into a soluble complex ion.

Cloud is a colloidal dispersion of Water drops in a dispersion medium of air. Clouds are formed when moist and warm air rises from the seas and cools as they reach the atmosphere.

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.

Electroplating is the process of coating a metal with a thin layer of another metal by electrolysis to improve the metal's corrosion resistance. The metals commonly used for electroplating are nickel, chromium, cadmium, copper, gold, palladium, platinum, ruthenium, silver, tin and zinc.

When a helium atom loses an electron it becomes a positive helium ion. When an atom gains/loses an electron, the atom becomes charged, and is called an ion. If a neutral atom gains an electron, it becomes negative. This kind of ion is called an anion. If a neutral atom loses an electron, it becomes positive. This kind of ion is called a cation.

Dry Ice is the common name for solid carbon dioxide (CO₂). It gets this name because it does not melt into a liquid when heated; instead, it changes directly into a gas (a process known as sublimation).