Kc and Ka
Concentration of products/concentrations of reactants =Kc
moles go to the power of concentrations.
units vary, but if left at bottom of equation, they must be reversed.
Ka is the same, but ONLY looks at dissociation of 1 H+.
HX + aq >>> H+ and X-
So units are always moldm-3
pH and [H+] concentration
pH = -log[H+]
[H+] = 10^(-pH)
Strong acids fully dissociate, so the Concentration of [H+] is the same as the concentration of initial acid. So Concentration can be quickly substituted for [H+] in -log[H+]= pH
Ka and Pka
Like pH is the log of [H+] concentration, pKa is the log of Ka (acid dissociation constant)
Ka = 10^(-pKa)
Weak acids do not fully dissociate, so you must work out Ka for the reaction. Concentration of the two products is the same so square the h+ concentration, and divide by the reactants e.g.
ka = [H+]^2 / [reactants]
If you are looking for H+ concentration, to find pH, you:
[H+] = square root (Ka x [reactants]
enthalpy of neutralisation
Same as enthalpy of reaction, but ONLY for 1 mole of water.