Equilibrium highlights

Types of equilibrium 1 Physical Equilibrium—forward and reverse reactions of a physical reaction (a change in state). 2 Chemical Equilibrium—forward and reverse reactions of a chemical reaction.

arrows Different types of arrows:

Examples-Physical 1 Physical Equilibrium: --Liquid to gas of water --Solid to liquid --Solid to gas

Examples-chemical 2 Chemical Equilibrium --Creation of new substances (chemical change) Hydrogen fluoride and water into hydronium and fluoride ions: Sulfur dioxide and oxygen gas into sulfur trioxide

How to affect equilibrium --Not a change in rate, an equilibrium shift. --Le Chatelier’s Principle: equilibrium shifts in direction that relieves change. --Temperature, Pressure, and Concentration can affect direction of equilibrium. --For each, you will decide which direction the shift likely goes.

temperature If a reaction is exothermic, heat is given off as a product. If you increase heat, to counter-balance the shift would go __________. If you take heat away (cool off), the reaction shifts _____________. N2 + 3H2  2NH3 + Heat If a reaction is endothermic, heat is used as a reactant. If you increase heat, to counter-balance the shift would go _____________. If you take heat away (cool off), the reaction shifts _______________.

Pressure Analogy: squeezing a blown up balloon. --Which direction does pressure try to go toward? --So, in the reaction, an increase in pressure would cause ____________. --How could you actually increase pressure? N2 + 3H2  2NH3 + Heat

concentration --Chemical reactions don’t like it when you tamper with them. If you take something away, it will make more of it. If you add more of something, it will shift to produce more to counter-balance. --Analogy tea that isn’t too sugary. N2 + 3H2  2NH3 + Heat