Why is it necessary to make correction to the observed conductance in any conductometric titration?
conductivity increases continuously from the commencement. Hence, the salt present in the cell should be virtually completely dissociated; for a similar reason; the added reagent should also be as strong electrolyte. conductance is corrected for this effect, non linear titration curves result.
What is meant by corrected conductance?
The correction can be accomplished by multiplying the observed conductance either by total volume (V+V´) or by the factor (V+ V´)/V, where V is the initial volume of solution and V´ is the total volume of the reagent added.
What causes the change in conductivity during titration?
During an acid-base titration there will be changes in the conductivity of the solution reflecting the changing concentration of ions in solution, especially the changes in the concentration of highly mobile ions like H+(aq) and OH-(aq).
What is conductance in conductometric titration?
The conductometric titration curve is a plot of the measured conductance or conductivity values as a function of the volume of the NaOH solution added. After the equivalence point is achieved the conductivity increases rapidly due to the excess OH− ions.
Why does conductometric titration decrease conductance value?
Conductometric titrations, in which the species in the solution are converted to non-ionic for by neutralization, precipitation, etc. are of more value. hydrogen ions by the added cation as H+ ions react with OH− ions to form undissociated water. This decrease in the conductance continues till the equivalence point.
What are the advantages of conductometric titration over volumetric titration?
More accurate results are obtained by conductometric titrations because the end-point is determined graphically from a number of measurements and not from a single measurement as in volumetric titration. This titration can be used with colored or opaque solutions in which endpoint cannot be seen by the naked eye.
What are the factors on which conductance depends?
(1) Nature of electrolyte: The conductance of an electrolyte depends upon the number of ions present in the solution. Therefore, the greater the number of ions in the solution the greater is the conductance. The number of ions produced by an electrolyte depends upon its nature.
Why does conductance decrease in the precipitation titration?
While Ba(OH)2(aq) is in excess the addition of H2SO4(aq) produces a precipitate of BaSO4(aq) and water molecules, effectively removing ions from solution resulting in a decrease in the electrical conductance of the solution. The end point for the titration is where the 2 straight lines intersect.
Why does the conductance of Na2SO4 solution decrease on addition of BaCl2?
When Na2SO4 is added slowly from the burette to the solution of BaCl2, BaSO4 gets precipitated while the chloride ions remain unchanged. Ba2+ ions in the solution are replaced by free Na+ ions. Since the mobility of Na+ ions is less that of Ba2+ ions the conductance of the solution decreases.
What changes are observed in the specific conductance and molar conductance respectively on deleting the electrolytic solution?
Specific conductance increases and molar conductance decreases.
What is meant by conductance in chemistry?
Conductance is the expression of the ease of the passing of the electrons. In general, the greater the number of ions in the solution higher is the conductance. The conductivity of electrolytic solutions is governed by the following factors.
How does conductometric titration affect the conductivity of an acid?
The increase or decrease in the electrolytic conductivity in the conductometric titration process is linked to the change in the concentration of the hydroxyl and hydrogen ions (which are the two most conducting ions). The strength of an acid can be determined via conductometric titration with a standard solution of a base.
Why can’t conductometric titration be used for specific redox titration?
Only a few specific redox titrations can be done with the help of this process. This is because the conductivity of the solution is masked by relatively high hydronium ion concentration. The accuracy of conductometric titration is low when the concentrations of the electrolyte are high, making the titration process unsatisfactory.
How does equivalence point affect the conductance of a solution?
This is because the H + ions would be replaced by the cationic part of the base. After the equivalence point is reached, the concentration of the ionic entities will increase. This, in turn, increases the conductance of the solution.
What are the disadvantages of aconductometric titration?
Conductometric titration has numerous applications in acid-base titrations, redox titrations, precipitation titrations, and complex titrations. The two major disadvantages of this type of titration include: Only a few specific redox titrations can be done with the help of this process.