Equivalent, Molar Conductivity and Cell Constant

Q. The concentration of $A{g}^{+}$ ions in a saturated solution of $A{g}_2{C}_2{O}_4$ is $2.2\times {10}^{-4}mol{L}^{-1}$. The Solubility product of $A{g}_2{C}_2{O}_4$ is:

1. $4.5\times {10}^{-11}$
2. $5.3\times {10}^{-12}$
3. $2.42\times {10}^{-8}$
4. $2.66\times {10}^{-12}$

Q.

What is the formula for equivalent conductivity and how is it different from molar conductivity formula?

Q.

How does molar conductivity of strong and weak electrolytes vary with concentration?

Q.

What is conductance?

Q.

The conductivity of 0.20M solution of KCl at 298K is 0.0248 S $c{m}^{-1}$. Calculate its molar conductivity ?

Q. The molar conductivity of a $0.5mol/d{m}^3$ solution of $AgN{O}_3$ with electrolytic conductivity of $5.76\times {10}^{-3}Sc{m}^{-1}$ at 298 K is

1. $0.086Sc{m}^2/mol$
2. $28.8Sc{m}^2/mol$
3. $2.88Sc{m}^2/mol$
4. $11.52Sc{m}^2/mol$

Q.

Conductivity of 0.00241M acetic is $7.896\times {10}^{-5}Sc{m}^{-1}$

Calculate its molar conductivity. If ${\lambda }_m^{\circ }$ for acetic acid is $390.5Sc{m}^{2}mo{l}^{-1}$, what is its dissociation constant ?

Q. The electrical resistance of a column of 0.05 M NaOH solution of diameter 1 cm and length 50 cm is $5.55\times {10}^3$ ohm. Calculate its resistivity, conductivity, and molar conductivity.

1. $87.135\times {10}^{-2}ohmm,1.148S{m}^{-1},229.6\times {10}^{-4}S{m}^{2}mo{l}^{-1}$
2. $67.135\times {10}^{-2}ohmm,1.489S{m}^{-1},229.6\times {10}^{-4}S{m}^{2}mo{l}^{-1}$
3. $87.135\times {10}^{-2}ohmm,1.296S{m}^{-1},229.6\times {10}^{-4}S{m}^{2}mo{l}^{-1}$
4. $77.135\times {10}^{-2}ohmm,1.148S{m}^{-1},229.6\times {10}^{-4}S{m}^{2}mo{l}^{-1}$

Q.

The resistance of a conductivity cell containing 0.001 M KCl solution at 298 K is $1500\Omega$. What is the cell constant if conductivity of 0.001 M KCl solution at 298 K is $1.46\times {10}^{-3}Sc{m}^{-1}$

Q. Some standard electrode potentials at $298K$ are given below:
$P{b}^{2+}/Pb-0.13VN{i}^{2+}/Ni-0.24VC{d}^{2+}/Cd-0.40VF{e}^{2+}/Fe-0.44V$
To a solution containing $0.001M$ of $X^{2+}$ and $0.1M$ of $Y^{2+}$, the metal rods $X$ and $Y$ are inserted (at $298K$) and connected by a conducting wire. This resulted in dissolution of $X$. The correct combination(s) of $X$ and $Y$, respectively, is(are)
(Given: Gas constant, $R=8.314J{K}^{-1}mo{l}^{-1}$,
Faraday constant, $F=96500Cmo{l}^{-1}$)

1. $Cd$ and $Ni$
2. $Cd$ and $Fe$
3. $Ni$ and $Pb$
4. $Ni$ and $Fe$

Q.

The molar conductivities at infinite dilution of barium chloride, sulphuric acid and hydrochloric acid are $280,860and426Sc{m}^{2}mo{l}^{-1}$ respectively. The molar conductivity at infinite dilution of barium sulphate is _____ $Sc{m}^{2}mo{l}^{-1}$. (Round off to the Nearest Integer).

Q. The conductivity of a saturated solution of $BaS{O}_4$ is $3.06\times {10}^{-6}ohm{}^{-1}cm{}^{-1}$ and its molar conductance is $1.53ohm{}^{-1}c{m}^{2}mol{}^{-1}$. What will be the the $K_{sp}\text{of}BaS{O}_4$ ?

1. $4\times {10}^{-6}$

2. $2.5\times {10}^{-9}$

3. $4\times {10}^{-12}$

4. $2.5\times {10}^{-13}$

Q.

Molar conductances of $BaC{l}_2,H_{2}S{O}_4$ and HCl at infinite dilutions are $x_1,x_2$ and $x_3$ respectively. Equivalent conductance of $BaS{O}_4$ at infinite dilution will be :

1. $\frac{(x_1+x_2-x_3)}{2}$

2. $x_1+x_2-2x_3$

3. $\frac{(x_1-x_2-x_3)}{2}$

4. $\frac{(x_1+x_2-2x_3)}{2}$

Q. If the ionic equivalent conductivities of $K^{+}A{l}^{3+},\text{and}S{O}_4^{2-}$ ions are 4, 4, and 1 $Sc{m}^{2}E{q}^{-1}$ , respectively. Calculate the value of ${\wedge }_{eq}^0$ for Potash alum $(K_{2}S{O}_4.A{l}_2{\left(S{O}_4\right)}_3.24H_{2}O)$

Q.

The cell constant of a conductivity cell _____________.

1. changes with the change of electrolyte

2. changes with the change of concentration of electrolyte

3. changes with the temperature of the electrolyte

4. remains constant for a cell

Q. The molar conductivity of a $0.5mol/d{m}^3$ solution of $AgN{O}_3$ with electrolytic conductivity of $5.76\times {10}^{-3}Sc{m}^{-1}$ at 298 K is

1. $0.086Sc{m}^2/mol$
2. $28.8Sc{m}^2/mol$
3. $2.88Sc{m}^2/mol$
4. $11.52Sc{m}^2/mol$

Q.

Conductivity (unit Siemens) is directly proportional to area of the vessel and the concentration of the solution in it and is inversely proportional to the length of the vessel then the unit of the constant of proportionality is

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Q. The resistance of 0.01 N solution of an electrolyte is 210 $\Omega$ at 298 K with a cell constant of 0.88 $c{m}^{-1}$. Calculate the conductivity and equivalent conductivity of the solution.

1. $7.19\times {10}^{-3}oh{m}^{-1}c{m}^{-1},719.05Sc{m}^{2}e{q}^{-1}$
2. $4.19\times {10}^{-3}oh{m}^{-1}c{m}^{-1},419.05Sc{m}^{2}e{q}^{-1}$
3. $5.19\times {10}^{-3}oh{m}^{-1}c{m}^{-1},519.05Sc{m}^{2}e{q}^{-1}$
4. $6.19\times {10}^{-3}oh{m}^{-1}c{m}^{-1},619.05Sc{m}^{2}e{q}^{-1}$

Q. A button cell used in watches functions as following $Zn\left(s\right)+A{g}_{2}O\left(s\right)+H_{2}O\left(l\right)\rightleftharpoons 2Ag\left(s\right)+Z{n}^{2+}\left(aq\right)+20H^{-}\left(aq\right)$ If half cell potentials are $Z{n}_{\left(aq\right)}^{2+}+2e^{-}\to Z{n}_{\left(s\right)}{E}^{\circ }=-0.76V$ $A{g}_2{O}_{\left(s\right)}+H_2{O}_{\left(l\right)}+2e^{-}\to 2Ag\left(s\right)+2O{H}_{\left(aq\right)}^{-}{E}^{\circ }=0.34V$ the cell potential will be :
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1. $1.10V$
2. $0.42V$
3. $0.84V$
4. $1.34V$

Q. The saturated solution in AgA and AgB has conductivity 37510*10 having Ksp 310*-14 and 110*-14 and limiting molar conductivity of Ag+ and A- are 60 and 80 what will be the limiting molar conductivity of B-

Q. The specific conductivity of a saturated solution of $AgCl$ is $3.40\times {10}^{-6}{\text{ohm}}^{-1}{\text{cm}}^{-1}$ at ${25}^{\circ }C$. If ${\lambda }_{Ag+}=62.3{\text{ohm}}^{-1}{\text{cm}}^2{\text{mol}}^{-1}$ and ${\lambda }_{C{l}^{-}}=67.7{\text{ohm}}^{-1}{\text{cm}}^2{\text{mol}}^{-1}$, the solubility of $AgCl$ at ${25}^{\circ }C$ is:
[1 mark]

1. $2.6\times {10}^{-5}\text{M}$
2. $4.5\times {10}^{-3}\text{M}$
3. $3.6\times {10}^{-5}\text{M}$
4. $3.6\times {10}^{-3}\text{M}$

Q.

Which one of the following substance has the highest proton affinity

1. H₂O

2. H₂S

3. NH₃

4. PH₃

Q. The $E^{\circ }$ for $C{l}_2/C{l}^{-}$ is $+1.36$, for $I_2/I^{-}$ is $+0.53$, for $A{g}^{+}/Ag$ is $+0.79,N{a}^{+}/Na$ is $–2.71$ and for $L{i}^{+}/Li$ is $–3.04$. Arrange the following ionic species in decreasing order of reducing strength: $I^{-},Ag,C{l}^{-},Li,Na$

Q.

Define conductivity and molar conductivity for the solution of an electrolyte. Discuss their variation with concentration ?

Q. A current of $2A$ was passed for $1h$ through a solution of $CuS{O}_{4}0.237g\text{of}C{u}^{2+}$ ions were discharged at cathode, The current efficiency is:

1. $26.1$%
2. $10$%
3. $42.2$%
4. $40.01$%

Q. At $300K$ , a concentration cell is formed by coupling two $Cu$ electrodes immersed in $CuS{O}_4$ solution .
Given, the concentration of $C{u}^{2+}$ in one electrode is 100 times than that of the other. Which of the following is/are true for the given concentration cell?

1. Spontaneous cell reaction is,
   $C{u}^{2+}(aq,xM)\to C{u}^{2+}(aq,100xM)$
2. Spontaneous cell reaction is,
   $C{u}^{2+}(aq,100xM)\to C{u}^{2+}(aq,xM)$
3. At $300K,E_{cell}=0.06V$
4. At $300K,E_{cell}=0.24V$

Q.

What is the effect of decreasing concentration on the molar conductivity of weak electrolyte .Define briefly

Q.

The boiling point of ethyl alcohol is 78.6°C. Explain it on the Kelvin scale.

Q. The standard reduction potential of normal calomel electrode and reduction potential of saturated calomel electrodes are $0.27$ and $0.33Volt$ respectively. What is the concentration of $C{l}^{-}$ in saturated solution of KCl ?

1. 
   $0.1M$
2. 
   $0.01M$
3. 
   $0.001M$
4. 
   None

Q. Given, $E_{F{e}^{3+}/Fe}^0=0.036V,E_{F{e}^{2+}/Fe}^0=-0.439V$. The value of standard electrode potential for the change, $F{e}^{3+}\left(aq\right)+e^{-}\to F{e}^{2+}\left(aq\right)$ will be :

1. $-0.403V$
2. $0.385V$
3. $0.986V$
4. $-0.270V$