What is a weak electrolyte? Explain the relation between the concentration of a weak electrolyte and molar conductivity with a suitable graph.

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(N/A) Weak electrolyte: Electrolytes that undergo partial ionization in their aqueous solution are known as weak electrolytes. They exhibit ionic equilibrium in their aqueous solution. For example,$CH_{3}COOH$,$NH_{4}OH$,etc.
$(b)$ $\Lambda_{m}$ of weak electrolyte solution and concentration: For such electrolytes,the change in $\Lambda_{m}$ with dilution is due to the increase in the degree of dissociation and consequently the number of ions in the total volume of solution that contains $1 \ mol$ of electrolyte.
According to Ostwald's dilution law,the molar conductivity of a weak electrolyte solution increases significantly with a decrease in the concentration of the solution.
$(c)$ Explanation of conductivity on dilution: The dissociation constant of a weak electrolyte like acetic acid is low at higher concentrations. As the solution is diluted,the degree of dissociation increases. Consequently,the total volume of solution containing $1 \ mol$ of weak electrolyte increases,and molar conductivity increases significantly due to the increase in the number of ions.
Limiting molar conductivity of weak electrolyte: The graph of $\Lambda_{m}$ versus $c^{1/2}$ is not linear; it is a curve. Because the curve does not intersect the y-axis at zero concentration,we cannot obtain the value of limiting molar conductivity $\Lambda_{m}^{\circ}$ by extrapolation.

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For a saturated solution of $Ag_{2}CrO_{4}$ at infinite dilution,$\lambda_{m}^{\infty}(Ag^{+}) = 127 \ \Omega^{-1} \ cm^{2} \ mol^{-1}$ and $\lambda_{m}^{\infty}(CrO_{4}^{2-}) = 246 \ \Omega^{-1} \ cm^{2} \ mol^{-1}$. If the specific conductance of the solution is $2 \times 10^{-2} \ \Omega^{-1} \ cm^{-1}$,calculate the solubility product $(K_{sp})$ of $Ag_{2}CrO_{4}$.

Match the following:
List-$I$List-$II$
$(A)$ Potential of hydrogen electrode at $pH = 10$$(I)$ $0.76 \ V$
$(B)$ $Cu^{2+}|Cu$$(II)$ $0.059$
$(C)$ $Zn|Zn^{2+}$$(III)$ $-0.591 \ V$
$(D)$ $\frac{2.303RT}{F}$$(IV)$ $0.337 \ V$
$(V)$ $-0.76 \ V$

$(a)$ $A-III, B-I, C-II, D-V$
$(b)$ $A-II, B-V, C-I, D-IV$
$(c)$ $A-III, B-IV, C-I, D-II$
$(d)$ $A-V, B-I, C-IV, D-II$

Tollen's reagent is used for the detection of aldehyde. When a solution of $AgNO_3$ is added to glucose with $NH_4OH$,gluconic acid is formed.
$Ag^{+} + e^{-} \rightarrow Ag ; E^{\circ}_{red} = 0.8 \ V$
$C_6H_{12}O_6 + H_2O \rightarrow C_6H_{12}O_7 + 2H^{+} + 2e^{-} ; E^{\circ}_{oxd} = -0.05 \ V$
$Ag(NH_3)_2^{+} + e^{-} \rightarrow Ag_{(s)} + 2NH_3 ; E^{\circ}_{red} = 0.337 \ V$
[Use $2.303 \times \frac{RT}{F} = 0.0592$ and $\frac{F}{RT} = 38.92$ at $298 \ K$]
$1.$ $2Ag^{+} + C_6H_{12}O_6 + H_2O \rightarrow 2Ag_{(s)} + C_6H_{12}O_7 + 2H^{+}$. Find $\ln K$ of this reaction.
$(A) \ 66.13 \quad (B) \ 58.38 \quad (C) \ 28.30 \quad (D) \ 46.29$
$2.$ When ammonia is added to the solution,$pH$ is raised to $11$. Which half-cell reaction is affected by $pH$ and by how much?
$(A) E_{oxd}$ will increase by a factor of $0.65 \ V$ from $E^{\circ}_{oxd}$
$(B) E_{oxd}$ will decrease by a factor of $0.65 \ V$ from $E^{\circ}_{oxd}$
$(C) E_{red}$ will increase by a factor of $0.65 \ V$ from $E^{\circ}_{red}$
$(D) E_{red}$ will decrease by a factor of $0.65 \ V$ from $E^{\circ}_{red}$
$3.$ Ammonia is always added in this reaction. Which of the following must be incorrect?
$(A) NH_3$ combines with $Ag^{+}$ to form a complex.
$(B) Ag(NH_3)_2^{+}$ is a stronger oxidising reagent than $Ag^{+}$.
$(C)$ In absence of $NH_3$,silver salt of gluconic acid is formed.
$(D) NH_3$ has affected the standard reduction potential of glucose/gluconic acid electrode.
Give the answer for questions $1, 2$ and $3$.

Molar conductances of $BaCl_2$,$H_2SO_4$,and $HCl$ at infinite dilutions are $x_1, x_2$,and $x_3$,respectively. Equivalent conductance of $BaSO_4$ at infinite dilution will be

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Chemical reactions involve the interaction of atoms and molecules. $A$ large number of atoms/molecules (approximately $6.023 \times 10^{23}$) are present in a few grams of any chemical compound,varying with their atomic/molecular masses. To handle such large numbers conveniently,the mole concept was introduced. This concept has implications in diverse areas such as analytical chemistry,biochemistry,electrochemistry,and radiochemistry. The following example illustrates a typical case involving a chemical/electrochemical reaction,which requires a clear understanding of the mole concept. $A$ $4.0 \ M$ aqueous solution of $NaCl$ is prepared and $500 \ mL$ of this solution is electrolysed. This leads to the evolution of chlorine gas at one of the electrodes (atomic mass: $Na=23, Hg=200; 1 \ F = 96500 \ C$).
$1.$ The total number of moles of chlorine gas evolved is:
$(A)$ $0.5$ $(B)$ $1.0$ $(C)$ $2.0$ $(D)$ $3.0$
$2.$ If the cathode is a $Hg$ electrode,the maximum weight $(g)$ of amalgam formed from this solution is:
$(A)$ $200$ $(B)$ $225$ $(C)$ $400$ $(D)$ $446$
$3.$ The total charge (coulombs) required for complete electrolysis is:
$(A)$ $24125$ $(B)$ $48250$ $(C)$ $96500$ $(D)$ $193000$

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