Download App

Electrochemistry Chemistry - Electrochemistry

Rajasthan Board (RBSE) - STD 12 Science - Chemistry (Rajasthan - English Medium). 405 questions in this chapter.

Question types

Electrochemistry question types

405 questions across 8 question groups — pick any mix to generate a Chemistry paper with step-by-step answer keys.

405
Questions
8
Question groups
5
Question types
Sample Questions

Electrochemistry questions

One sample from each question group in this chapter. Select any group above to see the full set with answer keys.

Q 6Assertion (A) & Reason (B) MCQ1 Mark
In these questions, a statement of assertion followed by a statement of reason is given. Choose the correct answer out of the following choices.
  1. Assertion and reason both are correct statements and reason is correct explanation for assertion.
  2. Assertion and reason both are correct statements but reason is not correct explanation for assertion.
  3. Assertion is correct statement but reason is wrong statement.
  4. Assertion is wrong statement but reason is correct statement.
Assertion: The conductivity of solution is greater than pure solvent.
Reason: Conductivity depends upon number of the ions present in solution.
View full solution →
Q 7Assertion (A) & Reason (B) MCQ1 Mark
In these questions, a statement of assertion followed by a statement of reason is given. Choose the correct answer out of the following choices.
  1. Assertion and reason both are correct statements and reason is correct explanation for assertion.
  2. Assertion and reason both are correct statements but reason is not correct explanation for assertion.
  3. Assertion is correct statement but reason is wrong statement.
  4. Assertion is wrong statement but reason is correct statement.
Assertion: Molar conductivity of a weak electrolyte at infinite dilution cannot be determined experimentally.
Reason: Kohlrausch law helps to find the molar conductivity of a weak electrolyte at infinite dilution.
View full solution →
Q 8Assertion (A) & Reason (B) MCQ1 Mark
In these questions, a statement of assertion followed by a statement of reason is given. Choose the correct answer out of the following choices.
  1. Assertion and reason both are correct statements and reason is correct explanation for assertion.
  2. Assertion and reason both are correct statements but reason is not correct explanation for assertion.
  3. Assertion is correct statement but reason is wrong statement.
  4. Assertion is wrong statement but reason is correct statement.
Assertion: The observed conductance depends upon the nature of the electrolyte and the concentration of the solution.
Reason: The cell constant of a cell depends upon the nature of the material of the electrodes.
View full solution →
Q 9Assertion (A) & Reason (B) MCQ1 Mark
In these questions, a statement of assertion followed by a statement of reason is given. Choose the correct answer out of the following choices.
  1. If both Assertion and Reason are correct and the Reason is a correct explanation of the Assertion.
  2. If both Assertion and Reason are correct but Reason is not a correct explanation of the Assertion.
  3. If the Assertion is correct but Reason is incorrect.
  4. If both the Assertion and Reason are incorrect.
Assertion : On increasing dilution, the specific conductance keep on increasing.
Reason : On increasing dilution, degree of ionisation of weak electrolyte increases and molality of ions also
increases.
View full solution →
Q 10Assertion (A) & Reason (B) MCQ1 Mark
In these questions, a statement of assertion followed by a statement of reason is given. Choose the correct answer out of the following choices.
  1. Assertion and reason both are correct statements and reason is correct explanation for assertion.
  2. Assertion and reason both are correct statements but reason is not correct explanation for assertion.
  3. Assertion is correct statement but reason is wrong statement.
  4. Assertion is wrong statement but reason is correct statement.
Assertion: Conductance of a substance increases with decrease in resistance.
Reason: The inverse of resistance is called conductance.
View full solution →
Q 192 Marks Questions2 Marks
Using the standard electrode potentials given in Table $3.1,$ predict if the reaction between the following is feasible:$ Fe^{3+} (aq)$ and $Br^– (aq)$
View full solution →
Q 213 Marks Question3 Marks
The molar conductivity of $0.025 mol L^{–1}$ methanoic acid is $46.1 S \ cm^2 mol^{–1}.$ Calculate its degree of dissociation and dissociation constant. Given $\lambda ^0 (H^+) = 349.6 S \ cm^2 mol^{–1}$ and $\lambda ^0 (HCOO^–) = 54.6 S \ cm^2 mol^{-1}.$
View full solution →
Q 223 Marks Question3 Marks
In the button cells widely used in watches and other devices the following reaction takes place:
$Zn(s) + Ag_2O(s) + H_2O(l) \rightarrow Zn^{2+}(aq) + 2Ag(s) + 2OH^– (aq)$
Determine $\triangle_\text{r}\text{G}^\ominus$ and $\text{E}^\ominus$ for the reaction.
View full solution →
Q 233 Marks Question3 Marks
Conductivity of $0.00241 M$ acetic acid is $7.896 \times 10^{–5} S \ cm^{–1}$. Calculate its molar conductivity and if $\wedge^\circ_\text{m}$ for acetic acid is $390.5 S \ cm^2\ mol^{–1},$ what is its dissociation constant?
View full solution →
Q 243 Marks Question3 Marks
Write the Nernst equation and emf of the following cells at $298\ K:$
$Sn(s) | Sn^{2+}(0.050\ M) || H^+ (0.020\ M) | H_2(g) (1\ bar) | Pt(s)$
View full solution →
Q 253 Marks Question3 Marks
The conductivity of sodium chloride at $298 K$ has been determined at different concentrations and the results are given below:
Concentration$/M$ $0.001$ $0.010$ $0.020$ $0.050$ $0.100$
$10^2\times k/S m^{-1}$ $1.237$ $11.85$ $23.15$ $55.53$ $106.74$
Calculate $\wedge_\text{m}$ for all concentrations and draw a plot between $\wedge_\text{m}$ and $\text{C}^\frac{1}{2}.$ Find the value of $\wedge^\circ_\text{m}.$
View full solution →
Q 26Case study (4 Marks)4 Marks
Standard electrode potentials are used for various processes :
  • It is used to measure relative strengths of various oxidants and reductants.
  • It is used to calculate standard cell potential.
  • It is used to predict possible reactions.
A set of half$-$reactions $($in acidic medium$)$ along with their standard reduction potential$, E^\circ\ ($in volt$)$ values are given below :
$\ce{I_2 + 2e^- \rightarrow 2I^- ; E^\circ = 0.54 V}$
$\ce{Cl_2 + 2e^- \rightarrow 2Cl^- ; E^\circ = 1.36 V}$
$\ce{Mn^{3+} +e^- \rightarrow Mn^{2+}; E^\circ = 1.50 V}$
$\ce{Fe^{3+} + e^- \rightarrow Fe^{2+}; E^\circ = 0.77 V}$
$\ce{O2 + 4H^+ + 4e^- \rightarrow 2H2O ; E^\circ = 1.23 V}$
The following questions are multiple choice questions. Choose the most appropriate answer :
  1. Which of the following statements is correct?
  1. $Cl^-$ is oxidised by $\ce{O_2}$.
  2. $Fe^{2+}$ is oxidised by iodine.
  3. $I^-$ is oxidised by chlorine.
  4. $Mn^{2+}$ is oxidised by chlorine.
  1. $Mn^{3+}$ is not stable in acidic medium, while $Fe^{3+}$ is stable because :
  1. $\ce{O2}$ oxidises $Mn^{2+}$ to $Mn^{3+}$
  2. $\ce{O2}$ oxidises both $Mn^{2+}$ to $Mn^{3+}$ and $Fe^{2+}$ to $Fe^{3+}$
  3. $Fe^{3+}$ oxidises $\ce{H2O}$ to $\ce{O2}$
  4. $Mn^{3+}$ oxidises $\ce{H2O}$ to $\ce{O2}$
  1. The strongest reducing agent in the aqueous solution is :
  1. $I^-$
  2. $Cl^-$
  3. $Mn^{2+}$
  4. $Fe^{2+}$
  1. The emf for the following reaction is :
$\text{I}_2+\text{KCl}\rightleftharpoons2\text{KI}+\text{Cl}_2$
  1. $-0.82 V$
  2. $+0.82 V$
  3. $-0.73 V$
  4. $+0.73 V$
  1. Which of the following statements is correct for the following reaction?
$Fe^{3+} + Mn^{2+} \rightarrow Fe^{2+ }+ Mn^{3+}$
  1. The emf of the cell is positive.
  2. $Fe^{3+}$ oxidises $Mn^{2+}$.
  3. The reaction does not occur.
  4. All are correct.
View full solution →
Q 27Case study (4 Marks)4 Marks
Nemst equation relates the reduction potential of an electrochemical reaction to the standard potential and activities of the chemical species undergoing oxidation and reduction. Let us consider the reaction $, \text{M}^{\text{n+}}_{(\text{aq})}\xrightarrow{\ \ \ \ \ \ \ \ }\text{nM}_\text{(s)}$ For this reaction, the electrode potential measured with respect to standard hydrogen electrode can be given as $\text{E}_{\Big(\frac{\text{M}^{\text{n+}}}{\text{M}}\Big)}=\text{E}^\circ_{\Big(\frac{\text{M}^\text{n+}}{\text{M}}\Big)}-\frac{\text{RT}}{\text{nF}}\text{ln}\frac{[\text{M}]}{[\text{M}^{\text{n}+}]}$ In these questions $(Q$. No. $i-iv),$ a statement of assertion followed by a statement ofreason is given. Choose the correct answer out of the following choices.
  1. Assertion and reason both are correct statements and reason is correct explanation for assertion.
  2. Assertion and reason both are correct statements but reason is not correct explanation for assertion.
  3. Assertion is correct statement but reason is wrong statement.
  4. Assertion is wrong statement but reason is correct statement.
  1. Assertion : For concentration cell, $\text{Zn}_{(\text{s})}|\text{ Zn}^{2+}_{\text{(aq)}}||\text{ Zn}^{2+}_{(\text{aq})}|\text{ Zn}\\\ \ \ \ \ \ \ \ \ \ \ \ \text{C}_1\ \ \ \ \ \ \ \ \text{C}_2$
For spontaneous cell reaction $, C_1 < C_2$
Reason : For concentration cell, $\text{E}_\text{cell}=\frac{\text{RT}}{\text{nF}}\log\frac{\text{C}_2}{\text{C}_1}$
For spontaneous reaction, $\text{E}_\text{cell}=+\text{ve}\Rightarrow\text{C}_2>\text{C}_1$
  1. Assertion : For the cell reaction, $\text{Zn}_{(\text{s})}+\text{Cu}^{2+}_{(\text{aq})}\xrightarrow{\ \ \ \ \ }\text{Zn}^{2+}_{(\text{aq})}+\text{Cu}_{(\text{s})}$ voltmeter gives zero reading at equilibrium.
Reason : At the equilibrium, there is no change in concentration of $\ce{Cu2+}$ and $\ce{Zn2+}$ ions.
  1. Assertion : The Nernst equation gives the concentration dependence of emf of the cell.
Reason : In a cell, current flows from cathode to anode.
  1. Assertion : Increase in the concentration of copper half cell in a cell, increases the emfofthe cell.
Reason : $\text{E}_\text{cell}=\text{E}^\circ_\text{cell}+\frac{0.059}{2}\log\frac{[\text{Cu}^{2+}]}{[\text{Zn}^{2+}]}$
  1. Assertion : Electrode potential for the electrode $\frac{\text{Mn}^+}{\text{Mn}}$ with concentration is given by the expression under $\text{STP}$ conditions.
$\text{E}=\text{E}^\circ+\frac{0.059}{\text{n}}\log[\text{Mn}^{+}]$
Reason : $\text{STP}$ conditions require the temperature to be $273K$.
View full solution →
Q 28Case study (4 Marks)4 Marks
The potential of each electrode is known as electrode potential. Standard electrode potential is the potential when concentration of each species taking part in electrode reaction is unity and the reaction is taking place at $298K$. By convention, the standard electrode potential of hydrogen $\text{(SHE)}$ is $0.0V$. The electrode potential value for each electrode process is a measure of relative tendency of the active species in the process to remain in the oxidised/ reduced form. The negative electrode potential means that the redox couple is stronger reducing agent than $\frac{\text{H}^+}{\text{H}_2}$ couple. A positive electrode potential means that the redox couple is a weaker reducing agent than the $\frac{\text{H}^+}{\text{H}_2}$ couple. Metals which have higher positive value of standard reduction potential form the oxides of greater thermal stability. In these questions $(Q$. No. $i-iv),$ a statement of assertion followed by a statement ofreason is given. Choose the correct answer out of the following choices.
  1. Assertion and reason both are correct statements and reason is correct explanation for assertion.
  2. Assertion and reason both are correct statements but reason is not correct explanation for assertion.
  3. Assertion is correct statement but reason is wrong statement.
  4. Assertion is wrong statement but reason is correct statement.
  1. Assertion : An electrochemical cell can be set $-$ up only if the redox reaction is spontaneous.
Reason : A reaction is spontaneous if the free energy change is negative.
  1. Assertion : The standard electrode potential of hydrogen is $0.0V.$
Reason : It is by convention.
  1. Assertion : The more negative is the standard reduction potential, greater is its ability to displace $H_2 $ from acid.
Reason : Strength of reducing agent increases with the increase in negative value of the standard reduction potential.
  1. Assertion : The negative value of standard reduction potential means that reduction takes place on this electrode with reference to hydrogen electrode.
Reason : The standard electrode potential of a half cell has a fixed value.
  1. Assertion : The absolute value of electrode potential cannot be determined experimentally.
Reason : The electrode potential values are generally determined with respect to $\text{SHE}$.
View full solution →
Q 29Case study (4 Marks)4 Marks
Electrical work done in unit time is equal to electrical potential multiplied by total charge passed. ln order to obtain maximum work from a cell, the charge has to be passed reversibly. The reversible work done by a cell is equal to decrease in its Gibb's energy. Hence, Gibb's energy of reaction is given by $\Delta\text{G}=\text{nFE}_\text{cell}$ Hence, Eis the emfof the cell and $nF$ is the amount of energy. In these questions $(Q$. No. $i-Iv),$ a statement of assertion followed by a statement ofreason is given. Choose the correct answer out of the following choices.
  1. Assertion and reason both are correct statements and reason is correct explanation for assertion.
  2. Assertion and reason both are correct statements but reason is not correct explanation for assertion.
  3. Assertion is correct statement but reason is wrong statement.
  4. Assertion is wrong statement but reason is correct statement.
  1. Assertion : $\Delta\text{G}^\circ=-\text{nFE}^\circ$
Reason : $E^\circ$ ​​​​​​​ should be positive for a spontaneous reaction.
  1. Assertion : An electrochemical cell can be set up only if the red ox reaction is spontaneous.
Reason : A reaction is spontaneous if free energy change is negative.
  1. Assertion : For an electrochemical cell, $\Delta\text{G}<0$ and $\text{E}_\text{cell}>0.$
Reason : The given cell is non $-$ spontaneous.
  1. Assertion : Current stops flowing when $E_\text{cell} = 0$.
Reason : Equilibrium of the cell reaction is attained.
  1. Assertion :$ E_\text{cell}$ should have a positive value for the cell to function.
Reason : $E_\text{cell} = E_\text{cathode} - E_\text{anode}$
View full solution →
Q 30Case study (4 Marks)4 Marks
All chemical reactions involve interaction of atoms and molecules. A large number of atoms/molecules are present in a few gram of any chemical compound varying with their atomic / molecular masses. To handle such large number conveniently, the mole concept was introduced. All electrochemical cell reactions are also based on mole concept. For example, a $4.0$ molar aqueous solution of $\ce{NaCl}$ is prepared and $500\ mL$ of this solution is electrolysed. This leads to the evolution of chlorine gas at one of the electrode. The amount of products formed can be calculated by using mole concept.
The following questions are multiple choice questions. Choose the most appropriate answer :
  1. The total number of moles of chlorine gas evolved is :
  1. $0.5$
  2. $1.0$
  3. $1.5$
  4. $1.9$
  1. If cathode is a $Hg$ electrode, then the maximum weight of amalgam formed from this solution is :
  1. $300g$
  2. $446g$
  3. $396g$
  4. $296g$
  1. The total charge $($coulomb$)$ required for complete electrolysis is :
  1. $186000$
  2. $24125$
  3. $48296$
  4. $193000$
  1. In the electrolysis, the number of moles of electrons involved are :
  1. $2$
  2. $1$
  3. $3$
  4. $4$
  1. In electrolysis of aqueous $\text{NaCl}$ solution when $Pt$ electrode is taken, then which gas is liberated at cathode?
  1. $\ce{H2}$ gas
  2. $\ce{Cl2}$ gas
  3. $\ce{O2}$ gas
  4. None of these.
View full solution →
Q 315 Marks Questions5 Marks
Match the items of Column $I$ and Column $II.$
 
Column $I$
 
Column $II$
$i.$
Lechlanche cell
 $a.$
Cell reaction $2H_2 + O_2 ⎯\rightarrow 2H_2O$
$ii.$
$Ni–Cd$ cell
 $b.$
Does not involve any ion in solution and is used in hearing aids.
$iii.$
Fuel cell
 $c.$
Rechargeable.
$iv.$
Mercury cell
 $d.$
Reaction at anode, $Zn ⎯\rightarrow Zn^{2+} + 2e^-$
 
 
 $e.$
Converts energy of combustion into electrical energy.
View full solution →
Q 325 Marks Questions5 Marks
A voltaic cell is set up at $25^\circ C$ with the following half$-$cells $Al^{3+} (0.001M)$ and $Ni^{2+} (0.50M).$ Write an equation for the reaction that occurs when the cell generates an electric current and determine the cell potential.
$(\text{Given:}\text{ E}^{\circ}_{\text{Ni}^{2+}/\text{Ni}}=-0.25\text{V,E}^{\circ}_{\text{Al}^{3+}/\text{Al}}=-1.66\text{V})$
View full solution →
Q 335 Marks Questions5 Marks
Match the terms given in Column I with the units given in Column II.
 
 Column I   Column II
i. $\text{K}$ a. $\text{I}\times\text{t}$
ii. $\wedge_{\text{m}}$ b. $\frac{\wedge_{\text{m}}}{\wedge^\circ_\text{m}}$
iii. $\alpha$ c. $\frac{\text{k}}{\text{c}}$
iv. $\text{Q}$ d. $\frac{\text{G}^*}{\text{R}}$
View full solution →
Q 345 Marks Questions5 Marks
Match the terms given in Column I with the units given in Column II.
 
 Column I   Column II
i. $\wedge_{\text{m}}$ a. Intensive property.
ii. $\text{E}^{\ominus}_{\text{Cell}}$ b. Depends on number of ions/volume.
iii. $\text{K}$ c. Extensive property.
iv. $\Delta_{\text{r}}\text{G}_{\text{Cell}}$ d. Increases with dilution.
View full solution →
Q 355 Marks Questions5 Marks
A voltaic cell is set up at $25^\circ C$ with the followinng half$-$cell: $\ce{Al | Al^{3+}(0.001M)}$ and $\ce{Ni |Ni^{2+}(0.50M)}$
Calculate the cell voltage $\text{E}^{\circ}_{\text{Ni}^{2+}/\text{Ni}}\Big[=-0.25\text{V,E}^{\circ}_{\text{Al}^{3+}/\text{Al}}=-1.66\text{V}\Big]$
View full solution →
Browse all question groups ↑

Generate a Electrochemistry paper free

Pick question groups from the list above, set marks and difficulty, and export a branded PDF with step-by-step answer keys. First 3 chapters free — no signup.

Download App
Generate Paper FreeAll Chemistry chapters