Advertisements
Advertisements
Question
Write three important steps required to determine molar conductivity.
Advertisements
Solution
- Determination of cell constant:
Cell constant is determined by using KCl solution of known concentration in the conductivity cell. The resistance of this KCl solution is measured by Wheatstone bridge.
Now, cell constant = `"k"_"KCl" xx "R"_"solution"`
Conductivity of KCl solution is known. Thus, cell constant is calculated. - Determination of conductivity of given solution:
KCl solution in the conductivity cell in step (1) is replaced by the given solution whose conductivity is to be measured. Its resistance is measured by the Wheatstone bridge. The conductivity of given solution is then calculated as:
k = `"Cell constant"/("R"_("solution"))` - Calculation of molar conductivity:
The molar conductivity of the given solution is then calculated using equation:
Λ = `(1000"k")/"c"`
APPEARS IN
RELATED QUESTIONS
The molar conductivity of 0.05 M BaCl2 solution at 25° C is 223Ω-1 cm2 mol-1. What is its conductivity?
Choose the most correct option.
Two solutions have the ratio of their concentrations 0.4 and ratio of their conductivities 0.216. The ratio of their molar conductivities will be ______.
Answer the following in one or two sentences.
Write the relationship between conductivity and molar conductivity and hence unit of molar conductivity.
Answer the following in brief.
Explain the effect of dilution of the solution on conductivity.
Kohlrausch law is applicable for the solution _______.
In case of weak electrolyte the graph Λ vs `sqrt"c"` is _______.
Calculate molar conductivities at zero concentration for CaCl2 and NaCl.
Given: molar ionic conductivities of Ca2+, Cl–, Na+ ions are respectively, 104, 76.4, 50.1 Ω–1 cm–2 mol–1
If resistivity of 0.8 M KCI solution is 2.5 × 10-3 Ω cm. Calculate molar conductivity of solution?
The molar conductances at infinite dilution `(∧_0)` for electrolytes B+A− and C+A− are 140 and 120 S cm2 mol−1. The molar conductance at infinite dilution for B+X− is 198 S cm2 mol−1. The `∧_0` (in S cm2 mol−1) of C+X− is __________.
The resistance of `1/10`M solution is 2.5 × 103 ohm. What is the molar conductivity of solution? (cell constant = 1.25 cm-1).
The conductivity of 0.02 M solution of NaCl is 2.6 × 10−2 S cm−1. What is its molar conductivity?
Conductivity of KCI solution is 0.0027 Ω−1 m−1 at 25°C. The resistance of the solution is 82.4 Ω. The cell constant is ____________ m−1.
The SI unit of resistivity and molar conductivity are respectively ____________.
The molar conductivities at infinite dilution for sodium acetate, HCI and NaCl are 91 S cm2 mol-1, 425.9 S cm2 mol-1 and 126.4 S cm2 mol-1 respectively. The molar conductivity of acetic acid at infinite dilution is ______.
The resistance of a conductivity cell containing 0.001 M KCl solution at 298 K is 1500 Ω. What is the cell constant if conductivity of 0.001 M KCI solution at 298 K is 0.146 × 10−3 S cm−1?
What is the common unit of conductivity if the dimensions are expressed in centimeter?
What is the value of cell constant if conductance and conductivity of a solution is same?
What is the conductivity of 0.01 M NaCl solution if resistance and cell constant of NaCl solution are 375 ohms and 0.5 cm-1 respectively at 298 K?
If the conductivity of 0.08 M KCl solution is 2 × 10-2 Ω-1, what is the molar conductivity of the solution?
The value of [H3O+] in mol lit–1 of 0.001 M acetic acid solution (Ka = 1.8 × 10–5) is ______.
What is the SI unit of conductivity?
Which of the following has least conductivity in aqueous solution?
Molar conductivities at infinite dilution of Mg2+ and Br- are 105.8 Ω-1 cm2 mol-1 and 78.2 Ω-1 cm2 mol-1 respectively. Calculate molar conductivity at zero concentration of MgBr2.
Explain the determination of molar conductivity of a weak electrolyte at infinite dilution or zero concentration using Kohlrausch's law.
Write the relation between molar conductivity and molar ionic conductivities for the electrolytes:
- Na2SO4
- AlCl3
