Determination of conductance of various solutions - Assignment Example

Download file to see previous pages 4. From the data collected in the experiment, the following have been classified as either strong acid, weak acid, strong base or weak base.
HCL- strong acid
HNO3- strong acid
KOH- strong base
CH3CO2H- weak acid
NH3- weak base
5. KNO3, Ca (NO3)2, Al (NO3)2, HNO3. All these compounds have the same anion i.e. NO3- but differ only in the cation present. This difference brings about the difference in their conductance. The differences arise due to the difference in mobility of the various cations. All those metals plus hydrogen have different mobility in aqueous form, therefore, will conduct electric current differently.
6. The conductance of KCl is 660µS while that of KNO3 is 2.9mS. These two values differ due to the conductance contributed by nitrate and chloride ions to the total conductance of the solution. Therefore based on the same principle NaNO3 is expected to have a higher conductance than NaCl.
7. From the conductance of KCl, HCl, and HNO3 the conductance of KNO3 can be calculated as:
LKNO3 = LKCl+ LHNO3 - LHCl
LKNO3 = 0.66mS+8.6mS-8.1mS
LKNO3 = 1.16mS.
8. a) The conductance value for tap water was 0.2mS signifying that it was a weak electrolyte. Therefore it did not contain any ionic impurities since they would have given a higher conductance value.
b) The tap water could have contained molecular impurities which were responsible for the small conductance recorded. These impurities partially dissolved in the aqueous solution and hence recorded the small conductance value observed. ...Download file to see next pagesRead More