text: how does ionic strength in aqueous solutions work? the ratio of h+ to oh- determines the ph but not the ionic strength.  things can have a very low ph but not hurt you because of their low ionic strength.  does this have to do with the rate of dissociation of the solute or maybe its concentration in the water?  i figure if an acid reads ph 3 and you put it in pure water it will read ph 3 no matter its concentration but the more you add the stronger the ionic strength... is that right? when the electrostatic interaction between the ions increases the ionic strength increases. it is not just the presence of ions that effects the ionic strength.   the interaction should also be there. for interaction, further study of polar and difference in electronegativity comes into picture. so it is not just the presence. and the number which effects the ionic strength.   but for ph the number matters. the number of hydrogen ions h+ and oh- ions matters which effects the ph.  hope that was clear enough. any doubts u can ask further.