- contact c. a process wherein the catalyst is a solid and the catalyzed reaction is produced after the reactants (usually gases) have made contact with the solid.
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ca·tal·y·sis kə-'tal-ə-səs n, pl -y·ses -.sēz a change and esp. increase in the rate of a chemical reaction induced by a catalyst
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ca·tal·y·sis (kə-talґə-sis) [Gr. katalysis dissolution] increase in the velocity of a chemical reaction or process produced by the presence of a substance that is not consumed in the net chemical reaction or process; negative catalysis denotes the slowing down or inhibition of a reaction or process by the presence of such a substance.Medical dictionary. 2011.