Notes For Chemistry 3

[Archimedes]

Industrial Chemistry      
The Equilibrium law:
   Many chemical reactions are reversible. This means that the products can react to reform the reactants. The double arrow symbol ⇋ is used to indicate if a reaction is reversible. For example: N2 (g) + O2 (g) ⇋ 2NO (g).
   When the rate of the reverse reaction equals the rate of the forward reaction a state of equilibrium is reached.
   At equilibrium the reaction does not stop. Both reactants and products are present at equilibrium but their concentration remains fixed.
 
   If the conditions for equilibrium are changed, the equilibrium established may be disturbed and the system may undergo changes to re-establish equilibrium.
   The general reversible reaction at equilibrium is :
aA + bB ⇋ cC + dD
The equilibrium constant K for this reaction is given by K = (〖[C]〗^c 〖[D]〗^d)/(〖[A]〗^a 〖〗^b )
Where [ ] is the concentration in mol/L or M.
Note: The [ ] of pure solids or pure liquids is 1.
   If the value of K is very small (<<1), only small concentrations of the product are present and reactants are favoured.
   If K is very large (>>1), the concentration of the products is greater than the concentration of the reactants and the production of products is favoured.
   The magnitude of K depends only on the temperature and the equation used for the reaction; it does not indicate how fast the reaction proceeds.
   For the reaction N2 (g) + O2 (g) ⇋ 2NO (g), the equilibrium expression is:
K = 〖[NO]〗^2/([N2][O2])
   In a homogenous reaction, all the reactants and products are in the same state or phase, as in the reaction above.

[mmonn1906]

I don't study chem but this looks very useful, good work.