jee main chemistry important questions | Electrochemistry jee main questions FREE

Q 1 :

Identify the factor from the following that does not affect electrolytic conductance of a solution. [2024]

The nature of solvent used.
Concentration of the electrolyte.
The nature of the electrode used.
The nature of the electrolyte added.

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(3)

1. HCl in water is almost 100 percent ionized whereas HCl in ${CCl}_{4}$ is almost unionised. The two solutions have different conductance. Hence conductance depends upon nature of solvent.

2. For strong as well as weak electrolyte, conductance increases with dilution.

3. Conductance does not depend upon nature of electrode used.

4. For same concentration, strong electrolyte has more conductance than weak electrolyte.

Q 2 :

For a strong electrolyte, a plot of molar conductivity against ${(concentration)}^{1 / 2}$ is a straight line, with a negative slope, the correct unit for the slope is [2024]

$S$ ${cm}^{2}$ ${mol}^{- 1}$ $L^{1 / 2}$
$S$ ${cm}^{2}$ ${mol}^{- 3 / 2}$ $L$
$S$ ${cm}^{2}$ ${mol}^{- 3 / 2}$ $L^{- 1 / 2}$
$S$ ${cm}^{2}$ ${mol}^{- 3 / 2}$ $L^{1 / 2}$

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(4)

For strong electrolytes, variation of molar conductivity $(Λ_{m})$ with concentration (C) is given by:

$Λ_{m} = Λ_{m}^{0} - A \sqrt{C}$ , where $Λ_{m}^{0}$ is limiting molar conductivity i.e., molar conductivity at infinite dilution.

From this equation, slope is $-$ A.

Substituting units of all terms:

${Scm}^{2} {mol}^{- 1} = {Scm}^{2} {mol}^{- 1} - (units of A) \sqrt{{mol L}^{- 1}}$

$units of A = \frac{{Scm}^{2} {mol}^{- 1}}{\sqrt{{mol L}^{- 1}}} = {Scm}^{2} {mol}^{- 3 / 2} L^{1 / 2}$

Q 3 :

Molar ionic conductivities of divalent cation and anion are 57 S ${cm}^{2} {mol}^{- 1}$ and 73 S ${cm}^{2} {mol}^{- 1}$ respectively. The molar conductivity of solution of an electrolyte with the above cation and anion will be: [2024]

$65 {S cm}^{2} {mol}^{- 1}$
$187 {S cm}^{2} {mol}^{- 1}$
$130 {S cm}^{2} {mol}^{- 1}$
$260 {S cm}^{2} {mol}^{- 1}$

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(3)

Salt of divalent cation $(A^{2 +})$ and divalent anion $(B^{-})$ is AB.

It dissociates in water as:

$AB ⇌ A^{2 +} + B^{2 -}$

By Kohlrausch's law:

$Λ_{M}^{\circ} (AB) = λ_{m}^{\circ} (A^{2 +}) + λ_{m}^{\circ} (B^{2 -})$

$Λ_{M}^{\circ} (AB) = (57 + 73) {S cm}^{2} {mol}^{- 1} = 130 {S cm}^{2} {mol}^{- 1}$

Q 4 :

Which out of the following is a correct equation to show change in molar conductivity with respect to concentration for a weak electrolyte, if the symbols carry their usual meaning: [2024]

$Λ_{m} - Λ_{m}^{0} + {AC}^{1 / 2} = 0$
$Λ_{m} - Λ_{m}^{°} - {AC}^{1 / 2} = 0$
$Λ_{m}^{2} C + K_{a} Λ_{m}^{° 2} - K_{a} Λ_{m} Λ_{m}^{°} = 0$
$Λ_{m}^{2} C - K_{a} Λ_{m}^{° 2} + K_{a} Λ_{m} Λ_{m}^{°} = 0$

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(4)

Consider solution of a weak electrolyte AB with concentration C mol/L, undergoing dissociation in water with degree of dissociation $α$ .

$AB(aq) ⇌ A^{+} (aq) + B^{-} (aq)$

$t = 0$ $C$

$t = \infty$ $C (1 - α)$ $C α$ $C α$

$K_{a} = \frac{[A^{+}] [B^{-}]}{[AB]} = \frac{C α \times C α}{C (1 - α)} = \frac{C α^{2}}{1 - α} - I$

$α$ is related to $Λ_{m}$ and $Λ_{m}^{°}$ as $α = \frac{Λ_{m}}{Λ_{m}^{°}} - II$

Put $α$ from II in I

$K_{a} = \frac{C {(\frac{Λ_{m}}{Λ_{m}^{°}})}^{2}}{1 - (\frac{Λ_{m}}{Λ_{m}^{°}})}$

$C {(\frac{Λ_{m}}{Λ_{m}^{°}})}^{2} = K_{a} - K_{a} (\frac{Λ_{m}}{Λ_{m}^{°}})$

$C {(\frac{Λ_{m}}{Λ_{m}^{°}})}^{2} + K_{a} (\frac{Λ_{m}}{Λ_{m}^{°}}) - K_{a} = 0$

$Λ_{m}^{2} C + K_{a} Λ_{m} Λ_{m}^{°} - K_{a} {(Λ_{m}^{°})}^{2} = 0$

Q 5 :

The values of conductivity of some materials at 298.15 K in ${S m}^{- 1}$ are $2.1 \times 10^{3},$ $1.0 \times 10^{- 16},$ $1.2 \times 10,$ $3.91,$ $1.5 \times 10^{- 2},$ $1 \times 10^{- 7},$ $1.0 \times 10^{3} .$ The number of conductors among the materials is ___________ . [2024]

(4)

Conductivity at 298.15 K (in ${Sm}^{- 1}$ )	Material	Classification
$2.1 \times 10^{3}$	sodium	conductor
$1.0 \times 10^{- 16}$	glass	insulator
$1.2 \times 10$	graphite	conductor
$3.91$	0.1M HCl	conductor
$1.5 \times 10^{- 2}$	Si	semiconductor
$1 \times 10^{- 7}$	CuO	semiconductor
$1 \times 10^{3}$	iron	conductor

Q 6 :

A conductivity cell with two electrodes (dark side) are half filled with infinitely dilute aqueous solution of a weak electrolyte. If volume is doubled by adding more water at constant temperature, the molar conductivity of the cell will [2024]

depend upon type of electrolyte
increase sharply
remain same or cannot be measured accurately
decrease sharply

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(3)

Upon dilution, molar conductivity increases because upon dilution, more of the electrolyte is dissociated and more charge carriers are created. Once all of the weak electrolyte is dissociated (at infinite dilution), then molar conductivity $(Λ_{m}^{o})$ does not increase further and becomes constant at a given temperature. $(Λ_{m}^{o})$ cannot be measured accurately for a weak electrolyte; it is calculated by Kohlrausch law.

Q 7 :

The molar conductivity for electrolytes A and B are plotted against $C^{1 / 2}$ as shown below. Electrolytes A and B respectively are: [2024]

A: Strong electrolyte, B: Strong electrolyte
A: Strong electrolyte, B: Weak electrolyte
A: Weak electrolyte, B: Strong electrolyte
A: Weak electrolyte, B: Weak electrolyte

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(3)

Q 8 :

Correct order of limiting molar conductivity for cations in water at 298 K is : [2025]

$H^{+} > {Na}^{+} > K^{+} > {Ca}^{2 +} > {Mg}^{2 +}$
$H^{+} > {Ca}^{2 +} > {Mg}^{2 +} > K^{+} > {Na}^{+}$
${Mg}^{2 +} > H^{+} > {Ca}^{2 +} > K^{+} > {Na}^{+}$
$H^{+} > {Na}^{+} > {Ca}^{2 +} > {Mg}^{2 +} > K^{+}$

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(2)

Among cations $H^{+}$ has highest molar conductivity in water.

This is because $H^{+}$ is conducted by transfer between water molecules.

For other ions, $Λ_{m}^{\circ} \propto charge$ . Thus

$Λ_{m}^{\circ} ({Ca}^{2 +}), Λ_{m}^{\circ} ({Mg}^{2 +}) > Λ_{m}^{\circ} (K^{+}), Λ_{m}^{\circ} ({Na}^{+})$

For ions carrying same charge, smaller ions are more hydrated, hence their limiting molar conductivity is lesser as $Λ_{m}^{\circ} \propto size .$

Thus $Λ_{m}^{\circ} ({Ca}^{2 +}) > Λ_{m}^{\circ} ({Mg}^{2 +}) and Λ_{m}^{\circ} (K^{+}) > Λ_{m}^{\circ} ({Na}^{+})$

Thus correct order of limiting molar conductivity is:

$H^{+} > {Ca}^{2 +} > {Mg}^{2 +} > K^{+} > {Na}^{+}$

Q 9 :

The molar conductivity of a weak electrolyte when plotted against the square root of its concentration, which of the following expected to be observed? [2025]

Molar conductivity decreases sharply with increase in concentration.
A small increase in molar conductivity is observed at infinite dilution.
A small decrease in molar conductivity is observed at infinite dilution.
Molar conductivity increases sharply with increase in concentration.

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(1)

With dilution, degree of dissociation of weak electrolyte increases hence number of charge carriers rise sharply and molar conductivity increases sharply.

Q 10 :

Given below are two statements : [2025]

Statement I : Mohr’s salt is composed of only three types of ions – ferrous, ammonium and sulphate.

Statement II : If the molar conductance at infinite dilution of ferrous, ammonium and sulphate ions are $x_{1}, x_{2}$ and $x_{3}$ S ${cm}^{2}$ ${mol}^{- 1}$ , respectively, then the molar conductance for Mohr’s salt solution at infinite dilution would be given by $x_{1} + x_{2} + 2 x_{3}$

In the light of the given statements, choose the correct answer from the options given below :

Both statements I and Statement II are false.
Statement I is false but Statement II is true.
Statement I is true but Statement II are false.
Both statements I and Statement II are true.

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(3)

Statement I

Mohr's salt: ${FeSO}_{4} . {({NH}_{4})}_{2} {SO}_{4} . 6 H_{2} O$

Statement II:

By Kohlrausch law

$Λ_{m}^{\circ} (Mohr's salt) = λ_{m}^{\circ} ({Fe}^{2 +}) + 2 λ_{m}^{\circ} ({NH}_{4}^{+}) + 2 λ_{m}^{\circ} ({SO}_{4}^{2 -})$

$= x_{1} + 2 x_{2} + 2 x_{3}$

Q 11 :

Given below is the plot of the molar conductivity vs $\sqrt{concentration}$ for KCl in aqueous solution.

If, for the higher concentration of KCl solution, the resistance of the conductivity cell is 100 $Ω$ , then the resistance of the same cell with the dilute solution is $‘ x ’ Ω$ .

The value of $x$ is ______ (Nearest integer) [2025]

(150)

$Λ_{m} = \frac{1000 \times κ}{C} \Rightarrow κ = \frac{Λ_{m} \times C}{1000}$

$Thus \frac{κ_{1}}{κ_{2}} = \frac{Λ_{m_{1}} \times C_{1}}{Λ_{m_{2}} \times C_{2}} = \frac{150 \times {(0.1)}^{2}}{100 \times {(0.15)}^{2}} = \frac{2}{3}$ ...(i)

$Also$

$R = ρ \frac{L}{a} = \frac{1}{κ} \times \frac{L}{a} \Rightarrow \frac{κ_{1}}{κ_{2}} = \frac{R_{2}}{R_{1}} = \frac{100}{x}$ ...(ii)

$Equating (i) and (ii) gives x = 150$

Q 12 :

0.2% (w/v) solution of NaOH is measured to have resistivity 870.0 m $Ω$ m. The molar conductivity of the solution will be ______ $\times 10^{2}$ mS ${dm}^{2}$ ${mol}^{- 1}$ . (Nearest integer) [2025]

(23)

$Molarity of NaOH (C) = \frac{(% w / v) \times 10}{M_{NaOH}}$

$= \frac{0.2 \times 10}{40} = 0.05 M$

$ρ = 870 mΩ m = 870 \times 10^{- 3} Ω \times 100 cm = 87 Ω cm$

$κ = \frac{1}{ρ} = \frac{1}{87} {S cm}^{- 1}$

$Λ_{m} = \frac{1000 κ}{C} {S cm}^{2} {mol}^{- 1}$

$= \frac{1000}{87 \times 0.05} {S cm}^{2} {mol}^{- 1} = 229.885 {S cm}^{2} {mol}^{- 1}$

$= 229.885 \times 1000 {mS (10}^{- 1} {dm)}^{2} {mol}^{- 1}$

$= 22.99 \times 10^{2} {mS dm}^{2} {mol}^{- 1}$

Q 13 :

The molar conductance of an infinitely dilute solution of ammonium chloride was found to be 185 S ${cm}^{2}$ ${mol}^{- 1}$ and the ionic conductance of hydroxyl and chloride ions are 170 and 70 S ${cm}^{2}$ ${mol}^{- 1}$ , respectively. If molar conductance of 0.02 M solution of ammonium hydroxide is 85.5 S ${cm}^{2}$ ${mol}^{- 1}$ , its degree of dissociation is given by $x \times 10^{- 1}$ .

The value of $x$ is _____. (Nearest integer) [2025]

(3)

By Kohlrausch law:

$Λ_{{NH}_{4} OH}^{\circ} = λ_{{NH}_{4}^{+}}^{\circ} + λ_{{OH}^{-}}^{\circ}$

$= (λ_{{NH}_{4}^{+}}^{\circ} + λ_{{Cl}^{-}}^{\circ}) + λ_{{OH}^{-}}^{\circ} - λ_{{Cl}^{-}}^{\circ}$

$= Λ_{{NH}_{4} Cl}^{\circ} + λ_{{OH}^{-}}^{\circ} - λ_{{Cl}^{-}}^{\circ}$

$= (185 + 170 - 70) {S cm}^{2} {mol}^{- 1}$

$= 285 {S cm}^{2} {mol}^{- 1}$

$α = \frac{Λ_{{NH}_{4} OH}}{Λ_{{NH}_{4} OH}^{\circ}} = \frac{85.5}{285} = 0.3 = 3 \times 10^{- 1}$

Q 14 :

Choose the correct representation of conductometric titration of benzoic acid vs sodium hydroxide. [2023]

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(3)

$C_{6} H_{5} COOH + NaOH \to C_{6} H_{5} COONa + H_{2} O$

The conductance first drops rapidly due to loss of more conducting $H^{+}$ already in the solution.
However soon, due to common ion effect of $C_{6} H_{5} {COO}^{-}$ the free $H^{+}$ concentration in solution is almost negligible, and then the added NaOH only increases the number of ions by forming more of $C_{6} H_{5} COONa$ .
At the end point, the conductance rises much more rapidly due to addition of ${OH}^{-}$ which has higher conductivity.

Q 15 :

Following figure shows dependence of molar conductance of two electrolytes on concentration. $Λ_{m}^{°}$ is the limiting molar conductivity.

The number of incorrect statement(s) from the following is __________ . [2023]

(A) $Λ_{m}^{°}$ for electrolyte A is obtained by extrapolation.

(B) For electrolyte B, $Λ_{m}$ vs $\sqrt{c}$ graph is a straight line with intercept equal to $Λ_{m}^{°}$ .

(C) At infinite dilution, the value of degree of dissociation approaches zero for electrolyte B.

(D) $Λ_{m}^{°}$ for any electrolyte A or B can be calculated using $λ °$ for individual ions.

(2)

Both (A) and (C) are incorrect.

Q 16 :

The resistivity of a 0.8 M solution of an electrolyte is $5 \times 10^{- 3} Ω cm$ . Its molar conductivity is ________ $\times 10^{4} Ω^{- 1} {cm}^{2} {mol}^{- 1}$ . (Nearest Integer) [2023]

(25)

$Resistivity (ρ) = 5 \times 10^{- 3} Ω cm$

$Molarity (M) = 0.8 M$

$Molar conductivity (λ_{M}) = \frac{1}{ρ} \times \frac{1000}{M}$

$= \frac{1}{5 \times 10^{- 3}} \times \frac{1000}{0.8}$

$= 0.25 \times 10^{6}$

$= 25 \times 10^{4} {cm}^{2} {mol}^{- 1}$

Q 17 :

$1 \times 10^{- 5}$ M ${AgNO}_{3}$ is added to 1 L of saturated solution of AgBr. The conductivity of this solution at 298 K is _________ $\times 10^{- 8}$ S $m^{- 1}$ .

[Given: $K_{sp} (AgBr) = 4.9 \times 10^{- 13}$ at 298 K

$λ_{{Ag}^{+}}^{\circ} = 6 \times 10^{- 3} {S m}^{2} {mol}^{- 1}$

$λ_{{Br}^{-}}^{\circ} = 8 \times 10^{- 3} {S m}^{2} {mol}^{- 1}$

$λ_{{NO}_{3}^{-}}^{\circ} = 7 \times 10^{- 3} {S m}^{2} {mol}^{- 1}$ ] [2023]

(13040)

$10^{- 5} {M AgNO}_{3}$ is added to saturate AgBr.

$K_{s p} = (s + 10^{- 5}) (s)$

$= s (10^{- 5}) = 4.9 \times 10^{- 13}$

$s = 4.9 \times 10^{- 8}$

Solution has

$[{Ag}^{+}] = 10^{- 5}, [{NO}_{3}^{-}] = 10^{- 5}$

$[{Br}^{-}] = 5 \times 10^{- 8}$

$λ = \frac{K \times 1000}{C}$

$K_{Total} = \frac{λ_{1} C_{1}}{1000} + \frac{λ_{2} C_{2}}{1000} + \frac{λ_{3} C_{3}}{1000}$

$\Rightarrow \frac{6 \times 10^{- 3} \times 10^{4} \times 10^{- 5}}{1000} + \frac{7 \times 10^{- 3} \times 10^{4} \times 10^{- 5}}{1000} + \frac{8 \times 10^{- 3} \times 10^{4} \times 5 \times 10^{- 8}}{1000}$

$\Rightarrow 6 \times 10^{- 7} + 7 \times 10^{- 7} + 40 \times 10^{- 10}$

$= 13.04 \times 10^{- 7} {S cm}^{- 1} = 13.04 \times 10^{- 5} {S m}^{- 1}$

$= 13040 \times 10^{- 8} {S m}^{- 1}$

$= 13040$

Q 18 :

The specific conductance of 0.0025 M acetic acid is $5 \times 10^{- 5} {S cm}^{- 1}$ at a certain temperature. The dissociation constant of acetic acid is ______ $\times 10^{- 7}$ . Consider limiting molar conductivity of ${CH}_{3} COOH$ as 400 S ${cm}^{2}$ ${mol}^{- 1}$ . [2023]

(66)

$Λ_{m} = \frac{1000 \times K}{C} = \frac{1000 \times 5 \times 10^{- 5}}{0.0025} = 20 {S cm}^{2} {mol}^{- 1}$

$α = \frac{20}{400} = \frac{1}{20}$

$K_{a} = \frac{C α^{2}}{1 - α^{2}} = \frac{0.0025 \times \frac{1}{20} \times \frac{1}{20}}{1 - \frac{1}{20}} = \frac{0.0025}{19 \times 20} = 66 \times 10^{- 7}$

Q 19 :

The number of correct statements from the following is ________.

(A) Conductivity always decreases with decrease in concentration for both strong and weak electrolytes.

(B) The number of ions per unit volume that carry current in a solution increases on dilution.

(C) Molar conductivity increases with decrease in concentration.

(D) The variation in molar conductivity is different for strong and weak electrolytes.

(E) For weak electrolytes, the change in molar conductivity with dilution is due to decrease in degree of dissociation. [2023]

(3)

(A) Conductivity always decreases with decrease in concentration for both strong and weak electrolytes.

(B) The number of ions per unit volume that carry current in a solution decreases on dilution.

(C) Molar conductivity increases with decrease in concentration.

(D) The variation in molar conductivity is different for strong and weak electrolytes.

(E) For weak electrolytes, the change in the molar conductivity with dilution is due to increase in degree of dissociation.

The correct statements are (A), (C) and (D).

Q 20 :

Molar conductivity of a weak acid HQ of concentration 0.18 M was found to be $\frac{1}{30}$ of the molar conductivity of another weak acid HZ with concentration 0.02 M. If $λ_{Q^{-}}^{\circ}$ happened to be equal to $λ_{Z^{-}}^{\circ}$ , then the difference of the $p K_{a}$ values of the two weak acids $(p K_{a} (HQ) - p K_{a} (HZ))$ is _______ (Nearest integer).

[Given: degree of dissociation $(α) ≪ 1$ for both weak acids, $λ °$ : limiting molar conductivity of ions] [2026]

(2)

$K_{a} (HQ) = C_{1} α_{1}^{2}$ $α_{1} = \frac{λ_{m} (HQ)}{λ_{m}^{\infty} (HQ)}$

$K_{a} (HZ) = C_{2} α_{2}^{2}$ $α_{2} = \frac{λ_{m} (HZ)}{λ_{m}^{\infty} (HZ)}$

$\frac{K_{a} (HQ)}{K_{a} (HZ)} = \frac{C_{1}}{C_{2}} . {(\frac{α_{1}}{α_{2}})}^{2} = \frac{0.18}{0.02} {[\frac{λ_{m} (HQ)}{λ_{m}^{\infty} (HZ)}]}^{2}$

$\frac{K_{a} (HQ)}{K_{a} (HZ)} = 9 \times {(\frac{1}{30})}^{2} = \frac{1}{100}$

$p K_{a} (HQ) - p K_{a} (HZ) = 2$

Topic Question Set

Q 1 :

Identify the factor from the following that does not affect electrolytic conductance of a solution. [2024]

Q 2 :

For a strong electrolyte, a plot of molar conductivity against ${(concentration)}^{1 / 2}$ is a straight line, with a negative slope, the correct unit for the slope is [2024]

Q 3 :

Molar ionic conductivities of divalent cation and anion are 57 S ${cm}^{2} {mol}^{- 1}$ and 73 S ${cm}^{2} {mol}^{- 1}$ respectively. The molar conductivity of solution of an electrolyte with the above cation and anion will be: [2024]

Q 4 :

Which out of the following is a correct equation to show change in molar conductivity with respect to concentration for a weak electrolyte, if the symbols carry their usual meaning: [2024]

Q 5 :

The values of conductivity of some materials at 298.15 K in ${S m}^{- 1}$ are $2.1 \times 10^{3},$ $1.0 \times 10^{- 16},$ $1.2 \times 10,$ $3.91,$ $1.5 \times 10^{- 2},$ $1 \times 10^{- 7},$ $1.0 \times 10^{3} .$ The number of conductors among the materials is ___________ . [2024]

Q 6 :

A conductivity cell with two electrodes (dark side) are half filled with infinitely dilute aqueous solution of a weak electrolyte. If volume is doubled by adding more water at constant temperature, the molar conductivity of the cell will [2024]

Q 7 :

The molar conductivity for electrolytes A and B are plotted against $C^{1 / 2}$ as shown below. Electrolytes A and B respectively are: [2024]

Q 8 :

Correct order of limiting molar conductivity for cations in water at 298 K is : [2025]

Q 9 :

The molar conductivity of a weak electrolyte when plotted against the square root of its concentration, which of the following expected to be observed? [2025]

Q 12 :

0.2% (w/v) solution of NaOH is measured to have resistivity 870.0 m $Ω$ m. The molar conductivity of the solution will be ______ $\times 10^{2}$ mS ${dm}^{2}$ ${mol}^{- 1}$ . (Nearest integer) [2025]

Q 14 :

Choose the correct representation of conductometric titration of benzoic acid vs sodium hydroxide. [2023]

Q 16 :

The resistivity of a 0.8 M solution of an electrolyte is $5 \times 10^{- 3} Ω cm$ . Its molar conductivity is ________ $\times 10^{4} Ω^{- 1} {cm}^{2} {mol}^{- 1}$ . (Nearest Integer) [2023]

Q 18 :

The specific conductance of 0.0025 M acetic acid is $5 \times 10^{- 5} {S cm}^{- 1}$ at a certain temperature. The dissociation constant of acetic acid is ______ $\times 10^{- 7}$ . Consider limiting molar conductivity of ${CH}_{3} COOH$ as 400 S ${cm}^{2}$ ${mol}^{- 1}$ . [2023]

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Topic Question Set

Q 1 : Identify the factor from the following that does not affect electrolytic conductance of a solution. [2024]

Q 2 : For a strong electrolyte, a plot of molar conductivity against (concentration)1/2 is a straight line, with a negative slope, the correct unit for the slope is [2024]

Q 3 : Molar ionic conductivities of divalent cation and anion are 57 S cm2 mol-1 and 73 S cm2 mol-1 respectively. The molar conductivity of solution of an electrolyte with the above cation and anion will be: [2024]

Q 4 : Which out of the following is a correct equation to show change in molar conductivity with respect to concentration for a weak electrolyte, if the symbols carry their usual meaning: [2024]

Q 5 : The values of conductivity of some materials at 298.15 K in S m-1 are 2.1×103, 1.0×10-16, 1.2×10, 3.91, 1.5×10-2, 1×10-7, 1.0×103.The number of conductors among the materials is ___________ . [2024]

Q 6 : A conductivity cell with two electrodes (dark side) are half filled with infinitely dilute aqueous solution of a weak electrolyte. If volume is doubled by adding more water at constant temperature, the molar conductivity of the cell will [2024]

Q 7 : The molar conductivity for electrolytes A and B are plotted against C1/2 as shown below. Electrolytes A and B respectively are: [2024]

Q 8 : Correct order of limiting molar conductivity for cations in water at 298 K is : [2025]

Q 9 : The molar conductivity of a weak electrolyte when plotted against the square root of its concentration, which of the following expected to be observed? [2025]

Q 12 : 0.2% (w/v) solution of NaOH is measured to have resistivity 870.0 mΩ m. The molar conductivity of the solution will be ______ ×102 mS dm2 mol-1. (Nearest integer) [2025]

Q 14 : Choose the correct representation of conductometric titration of benzoic acid vs sodium hydroxide. [2023]

Q 16 : The resistivity of a 0.8 M solution of an electrolyte is 5×10-3Ωcm. Its molar conductivity is ________ ×104Ω-1cm2 mol-1. (Nearest Integer) [2023]

Q 17 : 1×10-5 M AgNO3 is added to 1 L of saturated solution of AgBr. The conductivity of this solution at 298 K is _________ ×10-8 S m-1. [Given: Ksp(AgBr)=4.9×10-13 at 298 K λAg+∘=6×10-3 S m2mol-1 λBr-∘=8×10-3 S m2mol-1 λNO3-∘=7×10-3 S m2mol-1] [2023]

Q 18 : The specific conductance of 0.0025 M acetic acid is 5×10-5 S cm-1 at a certain temperature. The dissociation constant of acetic acid is ______ ×10-7. Consider limiting molar conductivity of CH3COOH as 400 S cm2 mol-1. [2023]

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Q 1 :

Identify the factor from the following that does not affect electrolytic conductance of a solution. [2024]

Q 2 :

For a strong electrolyte, a plot of molar conductivity against ${(concentration)}^{1 / 2}$ is a straight line, with a negative slope, the correct unit for the slope is [2024]

Q 3 :

Molar ionic conductivities of divalent cation and anion are 57 S ${cm}^{2} {mol}^{- 1}$ and 73 S ${cm}^{2} {mol}^{- 1}$ respectively. The molar conductivity of solution of an electrolyte with the above cation and anion will be: [2024]

Q 4 :

Which out of the following is a correct equation to show change in molar conductivity with respect to concentration for a weak electrolyte, if the symbols carry their usual meaning: [2024]

Q 5 :

The values of conductivity of some materials at 298.15 K in ${S m}^{- 1}$ are $2.1 \times 10^{3},$ $1.0 \times 10^{- 16},$ $1.2 \times 10,$ $3.91,$ $1.5 \times 10^{- 2},$ $1 \times 10^{- 7},$ $1.0 \times 10^{3} .$ The number of conductors among the materials is ___________ . [2024]

Q 6 :

A conductivity cell with two electrodes (dark side) are half filled with infinitely dilute aqueous solution of a weak electrolyte. If volume is doubled by adding more water at constant temperature, the molar conductivity of the cell will [2024]

Q 7 :

The molar conductivity for electrolytes A and B are plotted against $C^{1 / 2}$ as shown below. Electrolytes A and B respectively are: [2024]

Q 8 :

Correct order of limiting molar conductivity for cations in water at 298 K is : [2025]

Q 9 :

The molar conductivity of a weak electrolyte when plotted against the square root of its concentration, which of the following expected to be observed? [2025]

Q 12 :

0.2% (w/v) solution of NaOH is measured to have resistivity 870.0 m $Ω$ m. The molar conductivity of the solution will be ______ $\times 10^{2}$ mS ${dm}^{2}$ ${mol}^{- 1}$ . (Nearest integer) [2025]

Q 14 :

Choose the correct representation of conductometric titration of benzoic acid vs sodium hydroxide. [2023]

Q 16 :

The resistivity of a 0.8 M solution of an electrolyte is $5 \times 10^{- 3} Ω cm$ . Its molar conductivity is ________ $\times 10^{4} Ω^{- 1} {cm}^{2} {mol}^{- 1}$ . (Nearest Integer) [2023]

Q 18 :

The specific conductance of 0.0025 M acetic acid is $5 \times 10^{- 5} {S cm}^{- 1}$ at a certain temperature. The dissociation constant of acetic acid is ______ $\times 10^{- 7}$ . Consider limiting molar conductivity of ${CH}_{3} COOH$ as 400 S ${cm}^{2}$ ${mol}^{- 1}$ . [2023]