Acids in aqueous solutions form hydronium ions

H₃O⁺

Able to give more than one hydrogen ion 

Gives first proton more easily that sucessive protons 

Plasma concentration of an acid 

It is the constant governing the ionization of weak acids 

OH^-

(Base)

[D]^d[C]^c

[A]^a[B]^b

Products/Reactants 

10^-pH

antilog of pH