Cryolite (Na3AlF6, sodium hexafluoroaluminate) does not contain oxygen. It occurs as glassy, colorless, white-reddish to gray-black prismatic monoclinic crystals. Cryolite is used as an insecticide and a pesticide. It is also used to give fireworks a yellow color.

Correct Option: C

Cryolite (Na3AlF6, sodium hexafluoroaluminate) does not contain oxygen. It occurs as glassy, colorless, white-reddish to gray-black prismatic monoclinic crystals. Cryolite is used as an insecticide and a pesticide. It is also used to give fireworks a yellow color.

Sodium chloride, also known as salt, common salt, table salt or halite, is an ionic compound with the chemical formula NaCl, representing equal proportions of sodium and chlorine. In the form of table salt, it is commonly used as a condiment and food preservative.

Correct Option: A

Sodium chloride, also known as salt, common salt, table salt or halite, is an ionic compound with the chemical formula NaCl, representing equal proportions of sodium and chlorine. In the form of table salt, it is commonly used as a condiment and food preservative.

Sodium bicarbonate (NaHCO₃) is also known as baking soda. It is a chemical leavening agent which is added to baked goods before cooking to produce carbon dioxide and cause them to ‘rise’.

Correct Option: B

Sodium bicarbonate (NaHCO₃) is also known as baking soda. It is a chemical leavening agent which is added to baked goods before cooking to produce carbon dioxide and cause them to ‘rise’.

Neon is used in neon discharge lamps and advertising signs because the neon lights are visible from long distances. Since the light of neon signs has a better penetrating power through fog and mist, the neon signs are also used in beacon lights for the safety of air and sea navigation.

Correct Option: D

Neon is used in neon discharge lamps and advertising signs because the neon lights are visible from long distances. Since the light of neon signs has a better penetrating power through fog and mist, the neon signs are also used in beacon lights for the safety of air and sea navigation.

Hydrochloric acid was historically called acidum salis, muriatic acid, and spirits of salt because it was produced from rock salt and green vitriol and later from the chemically similar substances common salt and sulfuric acid. Hydrochloric acid is found naturally in gastric acid.

Correct Option: C

Hydrochloric acid was historically called acidum salis, muriatic acid, and spirits of salt because it was produced from rock salt and green vitriol and later from the chemically similar substances common salt and sulfuric acid. Hydrochloric acid is found naturally in gastric acid.