The boiling points of the halogens increase going down the group. The vapor pressure of pure water at 25 o C is 23.77 mm Hg. Catalysts affect the reaction rate, but do not appear in the rate law since their concentration does not change. Catalysts are formed in one step of a reaction mechanism and consumed in another. Catalysts lower the activation energy for the reaction.
Catalysts usually change the mechanism for a reaction.
Catalysts may be insoluble in the reaction solvent. After 7.0 d the radioactivity is found to be 75 disintegrations per minute. Reduction is always accompanied by oxidation. An aqueous solution is prepared by dissolving 2.05 g of hemoglobin in 100.0 mL of solution. 1- F97 Version 2 1.