Hi,

This really depends on the situation.

This rule of thumb you suggest will work sometimes but will really depend on the situation.

A more general way to think about it is:

Bases accept protons therefore they become more positive charged as they form conjugate acids.

You can have a couple of scenarios, including:

1) B- + H+ --> HB(0) where (0) signifies a neutral molecule.

2) B(0) + H+ --> HB+

For acids, they tend to lose protons and become more negatively charged as they dissociate to form conjugate bases. You can have a couple of scenarios here too, including:

1) HA(0) --> H+ + A-

2) HA(1+) --> H+ + A(0)

This accounts for structural differences that could result in different charges. It also depends on the pH of the solution, different protonation states will be relevant at different pHs, and thus species will be differently charged.

I hope this helps.