I was under the impression that the electrical conductivity should increase initially, then begin to plateau, then fall past the saturation point for strong electrolytes. However, from this, I see that the conductivity of magnesium chloride does not follow this ( it is decreasing with increasing concentration) , BUT the data could be wrong though. Would someone mind explaining what I should expect when I conduct the experiment myself?
1 Answer
You simply started your data range at too high a concentration to see the initial increase. Semantic Scholar gives data for the conductivities of several aqueous electrolyte solutions at 25°C, including magnesium chloride. The strongly increasing portion of the magnesium chloride curve goes up to about 10%, which corresponds to about one molar (where your data happens to start).
-
$\begingroup$ Not increasing at an increasing g rate. Compare conductivities with the mass percents whose increments are non uniform (1%, 2%, 5%, 10%, etc.). 10% is just over 100 g/L including the increased density and the molecular weight of MgCl2 is 95. Finally your trend at >1M is not very strong and its direction at a given concentration may be affected by measurement uncertainties. $\endgroup$ Nov 22, 2020 at 9:52
-
$\begingroup$ If you want to go up to 1M what you choose is good. $\endgroup$ Nov 22, 2020 at 20:07