University:
Glendale Community College
Course:
CHM130 | Fundamental Chemistry
Academic year:

2020
Views:

53

Pages:

2
Author:

monicagennyw8u

16.1 Collision Theory  Molecules must hit/collide in order to react and make products Chapter 16: Chemical Equilibrium  A successful collision results in reactant bonds breaking and/or product bonds forming  To increase the # of successful collisions:  you need more collisions.  you need enough activation energy, Ea.  the molecules must be oriented correctly. Collision Theory – Effective Collisions Cl + NOCl → Cl2 + NO Rates of Reaction  To Increase the Rate of Reaction:  Increase [reactant], more reactants = more collisions  Increase temperature, molecules move faster = Correct orientation to facilitate reaction An effective collision results in reaction. more collisions AND more energy  Add a catalyst which provides an alternate reaction pathway with lower Ea  Activation Energy, Ea, is the minimum energy needed to react (turn reactants to products) Incorrect orientation does not favor reaction An ineffective collision results in no reaction. 16.2 Energy Profiles Energy Profiles  Transition state = in between reactants and products, the Exothermic, is H + or -? reactant bonds are ½ broken and product bonds ½ formed, so this is a very high energy and unstable species, exists less than a millisecond  H = product heat – reactant heat  Endothermic = reactants gain or absorb heat, heat is a reactant, heat enters the rxn; H is positive (> 0)  Reactants + Heat  Products  Exothermic = reactants lose or release heat, heat is a product, heat exits the rxn; H is negative (< 0)  Reactants  Products + Heat 1 16.2 Energy Profiles Endothermic, is H + or -? 16.2 Energy Profiles With Catalyst Chapter 16 Self-Test, p. 492  Try 1-2  Answers in Appendix J 2