Practice MCQ Questions and answers on Chemistry-GK

Monazite is an important ore for thorium, lanthanum, and cerium. It is often found in placer deposits. India, Madagascar, and South Africa have large deposits of monazite sands. The deposits in India are particularly rich in monazite.

The chemical used in voting inks is silver nitrate. Silver nitrate is preferred because it is soluble in water, and makes an inky black solution. When put on the skin, silver nitrate reacts with the salt present on it to form silver chloride that is insoluble in water, and clings to the skin, making it impossible to wash off with soap and water or even alcohol. Mysore Paints and Varnish Limited in Karnataka is only company in India authorised to produce the indelible ink.

The heaviest naturally stable element is uranium, but over the years physicists have used accelerators to synthesize larger, heavier elements. In 2006, physicists in the United States and Russia created element 118.

The colour of transition-metal compounds is normally associated with d-d transitions. However, some transition metal compounds show intense colour in solution in spite of absence of d-electrons. For example, the orange colour of TiBr₄, yellow colour of CrO₄^2-, orange colour of Cr₂O₂^7-, intense red colour of [Fe(SCN)₄] and deep purple of MnO₄ are not due to d—d transitions. In the case of MnO₄ ion, the color is due to charge transfer and not due to d-d transitions.

Zeolites are microporous, aluminosilicate minerals commonly used as commercial adsorbents and catalysts.

The coordination number of the unit cell is eight.

The product, 9-nitroanthracene is obtained from anthracene by the action of Nitric acid and acetic anhydride.

Cyanide poisoning causes death in seconds because it break the electron transport chain. It causes coma followed by cardiac arrest and death.

Peroxyacetyl nitrate is an unstable, highly oxygenated compound that exists only in the atmosphere. It is a key intermediate in the formation of the air pollutant ozone.

Lead is in the manufacture of storage batteries. It is used in ammunition (shot and bullets) and as a constituent of solder, type metal, bearing alloys, fusible alloys, and pewter.