What is the difference of a week and a strong acid.
Strong acid : dissociation HA = H + A^- is 100% 1 M HA = 1 M H+, pH = -logH+
Weak acid HA = H+ +A^- is less then 100% 1 M HA = maybe 0,8 H+ and 0,2 M HA not dissociated.
For this we have the Ka or pKa value. Ka = ( H+ + A^-)/HA, pKa = - log Ka, pH = pKa + log( A-/HA)