Re: How does mass of the ions affect the conductivity of electrolytes?

The conductivity of an electrolyte solution depends upon how many ions are dissolved in the solution. The number of ions depends upon the chemical nature of the compound and the relative weights of the atoms making up the ions.

Chemists are used to thinking in terms of "moles" rather than grams. Each element has a different intrinsic mass related to how many protons and neutrons are in its nucleus. This is commonly called the "atomic weight". This means that 1 gram of carbon (AW 12) contains more atoms that one gram of sulfur (AW 32). Because we can't see individual atoms, chemists have scaled up to grams: 12 grams of carbon contains 6.02 x 10²³ atoms of carbon, while the same number of sulfur atoms weighs 32 grams.

The formula weight of a compound is found by summing the atomic weights of all the atoms in a compound.

Consider one gram of some common electrolytes (I've used milli-moles for more convenient numbers. 1 mmol= 1/1000 mol):

So you can see that because different atoms weight different amounts, and different compounds have different numbers of ions, you can't judge conductivity on the basis of mass alone.