hydrogenation (hĪdrôjˈənāˌshən, hĪˌdrəjənāˈshən) [key], chemical reaction of a substance with molecular hydrogen, usually in the presence of a catalyst. A common hydrogenation is the hardening of animal fats or vegetable oils to make them solid at room temperature and improve their stability. Hydrogen is added (in the presence of a nickel catalyst) to carbon-carbon double bonds in the unsaturated fatty acid portion of the fat or oil molecule:;g318;none;1;g318;;;block;;;;no;1;139392n;51425n;;;;;h-gnation318;;;left;stack;;;;;CE5Another hydrogenation is the synthesis of methanol from carbon monoxide. Hydrogenation reactions are important in petroleum refining; production of gasoline by cracking involves destructive hydrogenation (hydrogenolysis), in which large molecules are broken down to smaller ones and reacted with hydrogen. Most hydrogenation reactions are reversible and proceed to favorable equilibria at high pressure and moderate temperature.

The Columbia Electronic Encyclopedia, 6th ed. Copyright © 2012, Columbia University Press. All rights reserved.

More on hydrogenation from Fact Monster:

  • tritium - tritium tritium , radioactive isotope of hydrogen with mass number 3. The tritium nucleus, called a ...
  • hydrogen peroxide - hydrogen peroxide hydrogen peroxide, chemical compound, H2O2, a colorless, syrupy liquid that is a ...
  • hydrogen fluoride - hydrogen fluoride hydrogen fluoride, chemical compound, HF, a colorless, fuming liquid or colorless ...
  • HYDROGEN - You cannot see, taste, or smell hydrogen, yet this element makes up over 90 per cent of matter. The Sun and stars are made of hydrogen gas. On Earth,
  • hydrogen - hydrogen hydrogen [Gr.,=water forming], gaseous chemical element; symbol H; at. no. 1; at. wt. ...

See more Encyclopedia articles on: Chemistry: General

Play Hangman

Play Poptropica

Play Quizzes

Play Tic Tac Toe