Reactions
Henri Moissan first isolated pure calcium in 1898 by reducing calcium iodide with pure sodium metal:
- CaI2 + 2 Na → 2 NaI + Ca
Calcium iodide can be formed by treating calcium carbonate, calcium oxide, or calcium hydroxide with hydroiodic acid:
- CaCO3 + 2 HI → CaI2 + H2O + CO2
Calcium iodide slowly reacts with oxygen and carbon dioxide in the air, liberating iodine, which is responsible for the faint yellow color of impure samples.
- 2 CaI2 + 2 CO2 + O2 → 2 CaCO3 + 2 I2
Read more about this topic: Calcium Iodide
Famous quotes containing the word reactions:
“Cuteness in children is totally an adult perspective. The children themselves are unaware that the quality exists, let alone its desirability, until the reactions of grownups inform them.”
—Leontine Young (20th century)
“In this Journal, my pen is a delicate needle point, tracing out a graph of temperament so as to show its daily fluctuations: grave and gay, up and down, lamentation and revelry, self-love and self-disgust. You get here all my thoughts and opinions, always irresponsible and often contradictory or mutually exclusive, all my moods and vapours, all the varying reactions to environment of this jelly which is I.”
—W.N.P. Barbellion (1889–1919)
“We have all had the experience of finding that our reactions and perhaps even our deeds have denied beliefs we thought were ours.”
—James Baldwin (1924–1987)