Electrical Units and Conductance

What is the equivalent conductance of NaCl at infinite dilution at 25°C?

110.45 ohm⁻¹
146.45 ohm⁻¹
126.45 ohm⁻¹ (correct)
136.45 ohm⁻¹

What is the mathematical representation of the equivalent conductance of an electrolyte?

λa + λc (correct)
λa × λc
λa - λc
λa / λc

What is the application of Kohlrausch’s law in the given example?

To find the equivalent conductance of a mixture of electrolytes
To calculate the equivalent conductance of an electrolyte at infinite dilution (correct)
To calculate the equivalent conductance of an ion
To determine the end-point of acid-alkali reactions

What is the reason for the high conductance of the solution before the addition of an alkali in a conductometric titration?

The high mobility of H⁺ ions (C) Signup and view all the answers

What type of titrations involve the use of conductance measurements to determine the end-point?

Conductometric titrations (D) Signup and view all the answers

What is the unit of equivalent conductance?

ohm⁻¹ cm² eqvt⁻¹ (C) Signup and view all the answers

What is the unit of conductance of electrolytes?

Ohm-1 or mho or Siemens (S) (C) Signup and view all the answers

What is the unit of specific conductance of an electrolyte?

Ohm-1 cm-1 (A) Signup and view all the answers

What is the unit of equivalent conductance of an electrolyte?

Ohm-1 cm2 eqvt.-1 (D) Signup and view all the answers

What is Kohlrausch's Law (1875) related to?

Equivalent conductance of an electrolyte at infinite dilution (B) Signup and view all the answers

What is the symbol for specific conductance of an electrolyte?

κ (kappa) (D) Signup and view all the answers

What is the conductance of an electrolyte denoted by?

C (B) Signup and view all the answers

Why does the conductivity remain almost constant after the equivalence point in a conductometric titration?

The weak electrolyte NH4OH is not fully dissociated (B) Signup and view all the answers

What is the advantage of conductometric titrations over volumetric titrations in titrating weak acids against weak bases?

Sharp change of colour with indicators is not required (A) Signup and view all the answers

What is the purpose of keeping the temperature constant throughout the experiment?

To prevent any changes in the conductivity of the solution (B) Signup and view all the answers

Why should the titrant be 10 times stronger than the analyte?

To minimize the volume change during the titration (B) Signup and view all the answers

What is the advantage of conductometric titrations over volumetric titrations in terms of coloured solutions?

Titration can be carried out even with coloured solutions (C) Signup and view all the answers

What is the main difference between conductometric titrations and volumetric titrations in terms of end-point detection?

Conductance measurements vs. volume measurements (D) Signup and view all the answers

What happens to the conductance of the solution when NaOH is added to a weak acid?

It decreases initially and then increases (C) Signup and view all the answers

Why does the conductance of the solution decrease during the titration of a strong acid against a weak base?

Due to the replacement of fast moving H+ ions by slow moving NH4+ ions (A) Signup and view all the answers

What is the reason for the initial low conductance of the solution during the titration of a weak acid against a strong base?

Due to the poor dissociation of the weak acid (A) Signup and view all the answers

What happens to the H+ ions during the titration of a weak acid against a strong base?

They are consumed by OH- ions to form water molecules (C) Signup and view all the answers

What is the effect of the formation of sodium acetate during the titration of a weak acid against a strong base?

It suppresses the ionization of the weak acid (A) Signup and view all the answers

What is the trend of the conductance of the solution during the titration of a weak acid against a weak base?

It increases continuously (A) Signup and view all the answers

What is the oxidation half-reaction at the anode in a primary battery?

Zn (s) → Zn2+ + 2e- (D) Signup and view all the answers

What is the purpose of MnO2 in a primary battery?

To prevent H2 from collecting on the graphite rod (A) Signup and view all the answers

In a secondary battery, what is the oxidation half-reaction at the anode?

Pb (s) + H2SO4 (aq) → PbSO4 (s) + 2e- + 2H+ (aq) (D) Signup and view all the answers

What is the result of repeated charging of a secondary battery?

The hydrolysis of H2O into H2 and O2 (C) Signup and view all the answers

What is the primary function of a lithium-ion battery?

To store electrical energy through the movement of lithium ions (A) Signup and view all the answers

What is the purpose of adding distilled water to a secondary battery?

To keep the H2SO4 concentration constant (D) Signup and view all the answers