Why are weak acids and bases poor electrical conductors?
Weak acids or bases only ionize partially when dissolved in water, so the concentrations of ions in a weak acid solution is low.
For example, on dissolving acetic acid, the following equilibrium is established:
CH3COOH(aq) + H2O(l) ⇄ CH3COO-(aq) + H3O+(aq)
This equilibrium "lies to the left" which means when the reaction reaches a steady state, there will be much more of the uncharged reactant (left hand) side than the charged product side. The low concentrations of ions at equilibrium causes the solution to be a weak electrolyte.