Three groups of drugs are used to reduce the stickiness of platelets, thus preventing platelets from clumping together to form platelet plugs. The anti-platelet drugs are most effective in preventing abnormal blood clots from forming in arteries (as opposed to veins). Aspirin and dipyridamoleâ (Aggrenox).
In order to react, colliding molecules must have a total kinetic energy equal to or greater than some minimum value [Figure 14.13(b)]. The minimum energy required to initiate a chemical reaction is called the activation energy, Ea. The value of Ea varies from reaction to reaction.
43 Given the potential energy diagram for a chemical reaction: Which statement correctly describes the energy changes that occur in the forward reaction? (1) The activation energy is 10. kJ and the reaction is endothermic. (2) The activation energy is 10. kJ and the reaction is exothermic. (3) The activation energy is 50. kJ and the reaction is endothermic.