Carbon and its Compounds Test - 11

Copper is a good conductor of electricity and is used in electrical appliances. Sodium is very reactive and is stored under kerosene. Silver is tarnished by hydrogen sulphide. Tarnish is a thin layer of corrosion that forms over it. Graphite is an allotrope of carbon and a good conductor of electricity. It is used for making carbon electrodes and graphite electrodes in dry cells and electric arcs.

Iodine is a non-metal having a lustrous appearance. It has a shiny surface. Gallium is a metal that melts at room temperature. It can start melting in hand. Melting point of Gallium is 29.76^o C. Sodium is a soft metal. It can be cut easily with a knife. Mercury is a liquid at the room temperature. It is used in thermometers.

Ionic bonds are formed between cations and anions. Catenation is the linkage of atoms of the same element into longer chains. Catenation occurs most readily in carbon. Pyridine is added to alcohol to make it unsuitable for drinking. Most of the synthetic detergents are non-biodegradable. They cannot be decomposed by micro-organisms like the bacteria.

The oxyacetylene welding process uses a combination of ethyne (C₂H₂) and oxygen gas to provide a high temperature flame. It is commonly used to permanently join mild steel. . Alcohol meant for industrial purposes (fuel for spirit lamps) is made unfit for human consumption by adding small amounts (about 5%) of methanol to alcohol. The mixture is known as denatured spirit or denatured alcohol. Carbon dioxide turns lime water turns milky due to the formation of insoluble calcium carbonate. Esters have a fruity smell and are used in perfumes and cosmetics due to their characteristic odour.

Carbon compounds are usually poor conductors of heat and electricity. Carbon compounds are covalent compounds that have been formed by the sharing of electrons. They do not have strong forces of attraction between their molecules. They have weak interactions between their molecules. This leads to low melting points and boiling points.

Ethanol and propanol are alcohols and contain the functional group -OH. Ethanol is C₂H₅OH and propanol is C₃H₇OH. Ethanoic acid contains the carboxylic group (-COOH).

Water molecule is a covalent compound formed by the sharing of electrons between the hydrogen atoms and the oxygen atom. Metals like Na and Mg are electropositive in nature and form ionic compounds with electronegative non-metals.