Conductivity of Ionic Solutions
Basic Experiment

Print out the Datasheet, either from the HTML form or the .pdf form.
Use this sheet to guide you through the experiment.

Part I

This investigates the concentration dependence of the conductivity of Silver Nitrate solutions.

Record the conductivities for the suggested concentrations in µS. Since the cell constant is 1.00 cm, these values also represent the specific conductivity (K , kappa µS/cm),
Divide each of these values by the concentration in µmoles/cm3 and record the equivalent conductivity (L, lambda S-cm2/mole).
Since silver nitrate is a 1:1 electrolyte, equivalents and moles are identical.
 
 

Part II

Choose a concentration for this study. The default value of 0.0010 moles/liter is a convenient value for the 1:1 electrolytes. To maintain the same equivalent concentration, this concentration should be halved for the compounds with a divalent electrolyte (marked with two asterisks**).

Record the conductivity values in µS. It is slightly more convenient to fill in this table vertically by choosing a cation, then going through the anions.

Part III

For this table, the conductivity values for the sodium salt of each anion will be subtracted from the values for the corresponding potassium salt, ammonium salt, etc. This difference should appear to be relatively independent of the anion, suggesting that it represents the relative mobility of the cations. Circle any values that appear to violate this trend.

Part IV

For this table, the conductivity values for the chloride salt of each cation will be subtracted from the corresponding acetate salt, nitrate salt, etc. This difference should appear to be relatively independent of the cation, suggesting that it represents the relative mobility of the cations. Circle any values that appear to violate this trend.

Part V

Note the values in Tables III and IV that appear to violate the general trend. These indicate that the conductivities of some of the compounds in Table II cannot be approximated as the sum of the contributions of the ions. Suggest explanations for each of these cases.
 
 

Part VI

From the results in Table III, arrange the cations (include silver ion in this list) in order of increasing mobility (slowest -> fastest).
 
 

Part VI

From the results in Table IV, arrange the anions in order of increasing mobility (slowest -> fastest).

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