Answer to Question #69005 in Inorganic Chemistry for Bliss

Question

Calcium oxide is a constituent of all but one of the following

Answer 1

Calcium oxide, CaO, also known as lime or more specifically quicklime, is a white or grayish white solid produced in large quantities by roasting calcium carbonate so as to drive off carbon dioxide. At room temperature, CaO will spontaneously absorb carbon dioxide from the atmosphere, reversing the reaction. It will also absorb water, converting itself into calcium hydroxide and releasing heat in the process. The bubbling that accompanies the reaction is the source of its name as “quick,” or living, lime. The reaction of quicklime with water is sometimes used in portable heat sources. One of the oldest known products of a chemical reaction, quicklime is used extensively as a building material. It is sometimes used directly as a fertilizer, although calcium carbonate is usually preferred for that purpose. Large quantities of quicklime are used in various industrial neutralization reactions. Limelights, used in the 19th century in stage lighting, emit a very brilliant white light upon heating a block of calcium oxide to incandescence in an oxyhydrogen flame, hence the expression “to be in the limelight.”