Equilibria

Reactants are usually thought of as Reactants => Products, but some reactions are reversible, for instance, the Haber Process. If in a closed container, in somereactions, as soon as the products, are formed, they react together again and form the reactants, so eventually, there will be a mixture of reactants /and/products. = Equilibrium mixture.

If water was in a closed container, it would begin to evaporate, the volume of gas increasing, liquid, descreaing proportionally. And then, some gas molecules would start to re-enter the liquid and condense. Eventually evaporating and condensing gets equal. This is Dynamic Equilibrium. (Dynamic, because things are changing and moving, and Equilibrium because values are staying the same.)

Equilibrium conditions:

• Can only be reached in a closed system, so like, a tub. With a lid on. (Or a beaker if it takes place in a solvent. Apparently. I don't get that. Kersplain?)
  
• Equilibrium can go from either direction and the final equilibrium position will be the same. (Like if the was either water in a tub, or the same amount of water vapour, it would be the same.)
  
• It is dynamic. Reached when the two processes are the same.
• Equilibrium is reached when the macroscopic properties do not change. Macroscopic meaning visible.
  

Essentially:

1. You have products. Products are reacting. At the begining, the concentration of products is therefore, low.
   
2. As it continues, the concentration of products increases. As there is an increase in concentration, the rate of the reserve reaction speeds up.
   
3. A point is reached where the same amount of reactants > products are going on as the amount of products > reactants.
   
4. This is called dynamic equilibrium

Get it?

(: