Conductivity of Ionic Solutions

Q.

The conductivity of sodium chloride at 298 K has been determined at different concentrations and the results are given below :

$\begin{array}{cccccc}\frac{Concentration}{M}& 0.001& 0.010& 0.020& 0.050& 0.100\\ {10}^{-2}\times \frac{k}{S{m}^{-1}}& 1.237& 11.85& 23.15& 55.53& 106.74\end{array}$

Calculate ${\lambda }_m$ for all concentrations and draw a plot between ${\lambda }_m$ and $C^{\frac{1}{2}}$ Find the value of ${\lambda }_m^{\circ }$.

Q. The solubility of $Mg(OH{)}_2$, in pure water is $9.57\times {10}^{-3}g{L}^{-1}$. Calculate its solubility in $g{L}^{-1}$ in $0.02\text{M}Mg(N{O}_3{)}_2.$

1. $8.69\times {10}^{-6}$
2. $8.69\times {10}^{-4}$
3. $14.98\times {10}^{-6}$
4. $14.98\times {10}^{-4}$

Q. The limiting molar conductivities ${\Lambda }^0$
for $NaCl,KBr\text{and}KCl$ are $126,152\text{and}150Sc{m}^{2}mo{l}^{-1}$ respectively. The ${\Lambda }^0$ for $NaBr$ is:

1. $128Sc{m}^{2}mo{l}^{-1}$
   
2. $176Sc{m}^{2}mo{l}^{-1}$
   
3. $278Sc{m}^{2}mo{l}^{-1}$
4. $302Sc{m}^{2}mo{l}^{-1}$
   

Q. Equivalent conductivity of $BaC{l}_2,$ $H_{2}S{O}_4$ and $HCl$ are $x_1,x_2,and{x}_{3}Sc{m}^{2}e{q}^{-1}$
at infinite dilution. If conductivity of saturated $BaS{O}_4$ solution is $xSc{m}^{-1}$, then $K_{sp}$ of $BaS{O}_4$ is:

1. $\frac{500x}{(x_1+x_2-2x_3)}$

2. $\frac{{10}^6{x}^2}{{(x_1+x_2-2x_3)}^3}$

3. $\frac{2.5\times {10}^5{x}^2}{{(x_1+x_2-2x_3)}^2}$

4. $\frac{0.25x^2}{{(x_1+x_2-x_3)}^2}$

Q. $pH$ of $0.1M$ monobasic acid is measured to be $2$. Its osmotic pressure at a given temperature $TK$ is:

1. $0.1RT$
2. $0.11RT$
3. $1.1RT$
4. $0.01RT$

Q.

An aqueous solution contains an unknown concentration of ${\mathrm{Ba}}^{2+}$ . When $50\mathrm{mL}$ of a $1\mathrm{M}$ solution of ${\mathrm{Na}}_2{\mathrm{SO}}_4$ is added, ${\mathrm{BaSO}}_4$ just begins to precipitate. The final volume is $500\mathrm{mL}$. The solubility product of ${\mathrm{BaSO}}_4$ is $1\times {10}^{-10}$ . What is the original concentration of ${\mathrm{Ba}}^{2+}$ ?

1. $2\times {10}^{-9}\mathrm{M}$

2. $1.1\times {10}^{-9}\mathrm{M}$

3. $1.0\times {10}^{-9}\mathrm{M}$

4. $5\times {10}^{-9}\mathrm{M}$

Q. Calculate the solubility product of the sparingly soluble salt $Ca{F}_2$ from the following data:
The molar ionic conductances (at infinite dilution) of $C{a}^{2+}$ and $F^{-}$ ions are $104\times {10}^{-4}$ and $48\times {10}^{-4}S{m}^{2}mo{l}^{-1}$respectively. The specific conductance of the saturated solution of $Ca{F}_2$ at room temperature is $4.25\times {10}^{-3}S{m}^{-1}$ and the specific conductance of water used for preparing the solution is $2\times {10}^{-4}S{m}^{-1}$.

1. $8.48\times {10}^{-11}mol{}^{3}d{m}^{-9}$
2. $16.6\times {10}^{-12}mol{}^{3}d{m}^{-9}$
3. $3.32\times {10}^{-11}mol{}^{3}d{m}^{-9}$
4. $21.1\times {10}^{-11}mol{}^{3}d{m}^{-9}$

Q. 44. 1.0 molal aqueous solution of an electrolyte X_3Y_2 is 25% ionized.The boiling point of the solution is(K_b for H_2O=0.52)

Q.

A bottle of dry Ammonia$\left({\mathrm{NH}}_3\right)$and a bottle of dry Hydrogen chloride $\left(\mathrm{HCl}\right)$connected through a long tube are opened simultaneously at both ends. The white ammonium chloride (${\mathrm{NH}}_4\mathrm{Cl}$) ring first formed will be:

1. At the center of the tube

2. Near the hydrogen chloride bottle

3. Near the ammonia bottle

4. Throughout the length of the tube

Q. When $HN{O}_3\left(aq\right)$ is titrated with NaOH (aq) conductometrically, the graphical representation of this titration can be shown as

1. 
2. 
3. 
4. 

Q. Which of the following type of plot would you expect from the titration of $AgN{O}_3$ againest $KCl$ solution ?

1. 
2. 
3. 
4. 

Q. Assertion :Conductivity of weak electrolytic solution decreases with dilution whereas equivalent conductivity, molar conductivity increases with dilution. Reason: On dilution, the ionic mobility and number of ions present in solution increases but the number of ions per mL decreases.

1. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion.
2. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion.
3. Assertion is correct but Reason is incorrect.
4. Assertion is incorrect but Reason is correct.

Q. Maximum conductivity is seen in:

1. $N{a}_3\left[Ag\right(S_2{O}_3{)}_2]$ (0.1 M solution)
2. $FeS{O}_4.A{l}_2(S{O}_4{)}_3.24H_{2}O$ (0.1 M Solution)
   
3. $K_3\left[Fe\right(CN{)}_6]$ (0.1 M solution)
4. $K_2\left[Ni\right(CN{)}_4]$ (0.1 M solution)
   

Q. Why are HF & HFO₄ considered weak electrolytes?

Q. The density in g $m{L}^{-1}$ of a 3.6 M sulphuric acid solution, that is $29\%H_{2}S{O}_4$ (molar mass = 98 g $mo{l}^{-1}$) by mass will be:

1. 1.45
2. 1.65
3. 1.88
4. 1.22

Q. (D) NaBH4The relative reactivity of 10H, 20H and 3^° H in bromination reaction has been found to be1: 82 1600 respectively. In the reaction CH3CHCH3CH3 (excess) +Br2\xrightarrow[{hν}]{} CH3CH3BrCCH3+CH3-CH3CH-CH2Br the percentage yields of the products (A) and (B) are expected to be(A) 99.4%, 0.6%(B) 50%, 50%(C) 0.6%, 99.4%(D) 80%, 20%

Q. What is the correct increasing order of solubility of the following salt?

1. $Ca(HC{O}_3{)}_2<NaHC{O}_3<KHC{O}_3<Mg(HC{O}_3{)}_2$
2. $KHC{O}_3<Mg(HC{O}_3{)}_2<Ca(HC{O}_3{)}_2<NaHC{O}_3$
3. $Mg(HC{O}_3{)}_2<Ca(HC{O}_3{)}_2<NaHC{O}_3<KHC{O}_3$
4. $NaHC{O}_3<KHC{O}_3<Mg(HC{O}_3{)}_2<Ca(HC{O}_3{)}_2$

Q. Are all salts strong electrolytes?

Q. Statements about heavy water are given below:
(A) Heavy water is used in exchange reactions for the study of reaction mechanisms.
(B) Heavy water is prepared by exhaustive electrolysis of water.
(C) Heavy water has higher boiling point than ordinary water.
(D) Viscosity of ordinary water is greater than that of heavy water.

Choose the correct statements(s).

1. A and B only
2. A and D only
3. A, B and C only
4. A and C only

Q. The equivalent conductivity of a 0.01 N solution of a monobasic acid is 70.0 S $c{m}^{2}e{q}^{-1}$. If the equivalent conductivity of the acid at infinite dilution is 350 $Sc{m}^{2}e{q}^{-1}.$ Then

1. The degree of dissociation of the acid is 20 %
2. The dissociation constant of the acid is $5.0\times {10}^{-4}$
3. The osmotic pressure of the solution is 22.4 cm of Hg at 300K
4. The pH of the solution is 2.7

Q. You have $0.490$ g of unknown acid, $H_{2}A$, which reacts with $KOH$, according to following reaction:
$H_{2}A\left(aq\right)+2KOH\left(aq\right)\to K_{2}A\left(aq\right)+2H_{2}O\left(l\right)$.
If $100$ mL of $0.1M$ $KOH$ is required to titrate the acid to the second equivalence point, then the molar mass of acid is :

Q. The conductivity of sodium chloride at $298K$ has been determined at different concentrations and the results are given below:

Q. The equivalent conductivity of solutions of $BaC{l}_2,H_{2}S{O}_4\text{and}HCl$, are $x_1,x_2\text{and}{x}_3{\text{Scm}}^2{\text{eq}}^{-1}$ , respectively at infinite dilution. If the conductivity of saturated $BaS{O}_4$ solution is ${\text{x Scm}}^{-1}$ , then the $K_{sp}$ of $BaS{O}_4$ is:

1. $\frac{500x}{(x_1+x_2-2x_3)}$
2. $\frac{{10}^6{x}^2}{4{(x_1+x_2-2x_3)}^2}$
3. $\frac{0.25x^2}{{(x_1+x_2-x_3)}^2}$
4. $\frac{2.5\times {10}^5{x}^2}{{(x_1+x_2-x_3)}^2}$

Q. The correct order of the following complexes according to increasing conductivity of their solutions will be:
(i)$\left[Co\right(N{H}_3{)}_{3}C{l}_3]$
(ii)$\left[Co\right(N{H}_3{)}_{4}C{l}_2]Cl$
(iii)$\left[Co\right(N{H}_3{)}_6]C{l}_3$
(iv) $\left[Co\right(N{H}_3{)}_{5}Cl]C{l}_2$

1. (i) < (ii) < (iv) < (iii)
2. (ii) < (i) < (iii) < (iv)
3. (i) < (iii) < (ii) < (iv)
4. (iv) < (i) < (ii) < (iii)

Q. The equivalent conductance of $\frac{M}{32}$ solution of a weak monobasic acid is $8.0mhosc{m}^2$ and at infinite dilution is $400mhosc{m}^2$. The dissociation constant of this acid is:

1. $1.25\times {10}^{-4}$
2. $6.25\times {10}^{-4}$
3. $1.25\times {10}^{-6}$
4. $1.25\times {10}^{-5}$

Q. Maximum conductivity is seen in:

1. $K_3\left[Fe\right(CN{)}_6]$ (0.1 M solution)
2. $K_2\left[Ni\right(CN{)}_4]$ (0.1 M solution)
   
3. $FeS{O}_4.A{l}_2(S{O}_4{)}_3.24H_{2}O$ (0.1 M Solution)
   
4. $N{a}_3\left[Ag\right(S_2{O}_3{)}_2]$ (0.1 M solution)

Q.

An aqueous solution of $NaCl$ is heated with a Bunsen burner. The conductivity of the solution should

1. increase
2. decrease
3. remain constant

Q. Assertion :The 6th group cation are tested with their respective flame colours. Reason: The 6th group cations have very high solubility product.

1. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
2. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
3. Assertion is correct but Reason is incorrect
4. Both Assertion and Reason are incorrect

Q. 0.01 M $C{H}_{3}COOOH$ has 4.24% degree Of dissociation, the degree of dissociation of 0.1 M $C{H}_{3}COOH$ will be

1. 1.33%
2. 4.24%
3. 5.24%
4. 0.33%

Q.

1. True
2. False