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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?

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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).

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  • $\begingroup$ the document u sent uses mass % as the independent variable , but I am looking at mol/dm3. nonetheless, though, ill use 0.2 molarity, 0.4 molarity...1 molarity for my experiment. i just wanted to ask one thing though.. in the data u sent, the conductivity seems to be increasing at an increasing rate then increase at a decrease rate then plateau and then fall. im not sure why it is increasing at an increasing rate, i thought the curve is supposed to only increase at a decreasing rate then plateau and fall. thanks for the help. $\endgroup$ – Strawhat Nov 22 at 2:59
  • $\begingroup$ 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. $\endgroup$ – Oscar Lanzi Nov 22 at 9:52
  • $\begingroup$ I see, thanks. For my experiment, I need to choose 5 concentrations to test. Do you think 0.2,0.4,0.6,0.8 and 1 moles/dm3 is fine? The salts im using are magnesium chloride calcium chloride and barium chloride $\endgroup$ – Strawhat Nov 22 at 19:34
  • $\begingroup$ If you want to go up to 1M what you choose is good. $\endgroup$ – Oscar Lanzi Nov 22 at 20:07

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