Practice MCQ Questions and answers on Chemistry-GK

Rust stains can be a challenge to remove because the stain consists of tiny iron oxide particles. Acidic solutions work best for these stains. The important ingredient in these removers is an acid - usually oxalic or hydrofluoric acid. The remover ingredients combine with the iron and loosen it from the fabric, then hold it in suspension in the wash water.

Chloropicrin is a colourless liquid that is insoluble in water, with which it is stable. With a vapor pressure of 24 mm Hg, its volatility is between that of phosgene and mustard gas in persistency, although closer to phosgene because it is related to the compound. Tests have shown that chloropicrin causes humans to shut their eyes involuntarily. Chloropicrin can be absorbed systemically through inhalation, ingestion, and the skin. It is severely irritating to the lungs, eyes, and skin. Because of these properties, chloropicrin can only be delivered in shell form as a chemical weapon. Chloropicrin, today, is used as a fumigant to control pests found in the soil. Although less common, it can be used as a poison for vertebrates, such as rabbits. Chloropicrin is commonly used in combination with other fumigants, such as methyl bromide and sulfuryl fluoride, for increased potency and as a warning agent

Because of its unique internal atomic structure and its ready availability, silicon is widely used for solar cells. One of the elements of the Periodic Table of the Elements, silicon is known as a semiconductor, a substance that conducts electricity when there is a change to its environment.

DDT and BHC are hydrocarbons that may be carcinogenic. Laboratory animal studies showed effects on the liver and reproduction. DDT is considered a possible human carcinogen

Gunpowder consists of a mixture of Nitre, sulphur and charcoal.

detergent is a surfactant or a mixture of surfactants with cleansing properties in dilute solutions. These substances are usually alkylbenzene sulfonates, a family of compounds that are similar to soap but are more soluble in hard water, because the polar sulfonate (of detergents) is less likely than the polar carboxylate (of soap) to bind to calcium and other ions found in hard water.

Pb₃O₄ commonly known as red lead is used as sindhoor.

Methyl alcohol and water are used as an anti-freeze in radiators of automobiles.

Oxalic acid is used to remove iron and rust stains from clothes.

Acetone is not an anaesthetic agent in surgical operations.