Electrochemistry · JEE Main previous year questions

127 questions asked across 18 exam years, newest first

Year-wise papers Topic-wise questions

Practise this topic

2022 15 questions

Q812022 · 29 Jul 2022 · Shift 1· Numerical answer
Resistance of a conductivity cell (cell constant $129 m^{- 1}$ ) filled with $74.5 ppm$ solution of $KCl$ is $100 Ω$ (labelled as solution 1). When the same cell is filled with $KCl$ solution of $149 ppm$ , the resistance is $50 Ω$ (labelled as solution 2). The ratio of molar conductivity of solution 1 and solution 2 is i.e. $\frac{Λ _{1}}{Λ _{2}} = x \times 1 0^{- 3}$ . The value of $x$ is __________. (Nearest integer) Given, molar mass of $KCl$ is $74.5 g mo l^{- 1}$ .
Show answer
Answer: 1000
Q832022 · 29 Jul 2022 · Shift 2· Numerical answer
For a cell, $Cu (s) ∣ C u^{2 +} (0.001 M) ∥ A g^{+} (0.01 M) ∣ Ag (s)$ the cell potential is found to be $0.43 V$ at $298 K$ . The magnitude of standard electrode potential for $C u^{2 +} /Cu$ is ____ $\times 1 0^{- 2} V$ . $[Given : E_{A g^{+} /Ag}^{Θ} = 0.80 V and \frac{2.303 R T}{F} = 0.06 V]$
Show answer
Answer: 34
Q632022 · 28 Jul 2022 · Shift 1
Match List - I with List - II. | | List - I | | List - II | |---|---|---|---| | (A) | $C d (s) + 2 N i (O H)_{3} (s) \to C d O (s) + 2 N i (O H)_{2} (s) + H_{2} O (l)$ | (I) | Primary battery | | (B) | $Z n (H g) + H g O (s) \to Z n O (s) + H g (l)$ | (II) | Discharging of secondary battery | | (C) | $2 P b S O_{4} (s) + 2 H_{2} O (l) \to P b (s) + P b O_{2} (s) + 2 H_{2} S O_{4} (a q)$ | (III) | Fuel cell | | (D) | $2 H_{2} (g) + O_{2} (g) \to 2 H_{2} O (l)$ | (IV) | Charging of secondary battery | Choose the correct answer from the options given below:
1. A.(A) - (I), (B) - (II), (C) - (III), (D) - (IV)
2. B.(A) - (IV), (B) - (I), (C) - (II), (D) - (III)
3. C.(A) - (II), (B) - (I), (C) - (IV), (D) - (III)
4. D.(A) - (II), (B) - (I), (C) - (III), (D) - (IV)
Show answer
Answer: C
Q742022 · 27 Jul 2022 · Shift 1
Which of the following methods are not used to refine any metal? A. Liquation B. Calcination C. Electrolysis D. Leaching E. Distillation Choose the correct answer from the options given below:
1. A.B and D only
2. B.A, B, D and E only
3. C.B, D and E only
4. D.A, C and E only
Show answer
Answer: A
Q872022 · 27 Jul 2022 · Shift 1· Numerical answer
The conductivity of a solution of complex with formula $CoCl_{3} (NH_{3})_{4}$ corresponds to $1 : 1$ electrolyte, then the primary valency of central metal ion is _________.
Show answer
Answer: 3
Q642022 · 27 Jul 2022 · Shift 2
Given below are two statements : Statement I : For KI, molar conductivity increases steeply with dilution Statement II : For carbonic acid, molar conductivity increases slowly with dilution In the light of the above statements, choose the correct answer from the options given below :
1. A.Both Statement I and Statement II are true
2. B.Both Statement I and Statement II are false
3. C.Statement I is true but Statement II is false
4. D.Statement I is false but Statement II is true
Show answer
Answer: B
Q642022 · 25 Jul 2022 · Shift 2
The molar conductivity of a conductivity cell filled with 10 moles of $20 mL$ $NaCl$ solution is $Λ_{m 1}$ and that of 20 moles another identical cell having $80 mL$ $NaCl$ solution is $Λ_{m 2}$ . The conductivities exhibited by these two cells are same. The relationship between $Λ_{m 2}$ and $Λ_{m 1}$ is
1. A. $Λ_{m 2} = 2 Λ_{m 1}$
2. B. $Λ_{m 2} = Λ_{m 1} /2$
3. C. $Λ_{m 2} = Λ_{m 1}$
4. D. $Λ_{m 2} = 4 Λ_{m 1}$
Show answer
Answer: A
Q862022 · 25 Jul 2022 · Shift 2· Numerical answer
The spin-only magnetic moment value of $M^{3 +}$ ion (in gaseous state) from the pairs $C r^{3 +} / C r^{2 +}$ , $M n^{3 +} / M n^{2 +}$ , $F e^{3 +} / F e^{2 +}$ and $C o^{3 +} / C o^{2 +}$ that has negative standard electrode potential, is ____ $B.M.$ [Nearest integer]
Show answer
Answer: 4
Q832022 · 28 Jun 2022 · Shift 2· Numerical answer
For the given reactions $S n^{2 +} + 2 e^{-} \to Sn$ $S n^{4 +} + 4 e^{-} \to Sn$ the electrode potentials are ; $E_{S n^{2 +} / S n}^{o} = - 0.140 V$ and $E_{S n^{4 +} / S n}^{o} = + 0.010 V$ . The magnitude of standard electrode potential for $S n^{4 +} / S n^{2 +}$ i.e. $E_{S n^{4 +} / S n^{2 +}}^{o}$ is ____ $\times 1 0^{- 2} V$ . (Nearest integer)
Show answer
Answer: 16
Q842022 · 27 Jun 2022 · Shift 1· Numerical answer
The limiting molar conductivities of $NaI$ , $NaN O_{3}$ and $AgN O_{3}$ are $12.7$ , $12.0$ and $13.3 mS m^{2} mo l^{- 1}$ , respectively (all at $2 5^{\circ} C$ ). The limiting molar conductivity of $AgI$ at this temperature is ____ $mS m^{2} mo l^{- 1}$ .
Show answer
Answer: 14
Q652022 · 27 Jun 2022 · Shift 2
In 3d series, the metal having the highest $M^{2 +} / M$ standard electrode potential is :
1. A. $Cr$
2. B. $Fe$
3. C. $Cu$
4. D. $Zn$
Show answer
Answer: C
Q742022 · 26 Jun 2022 · Shift 1
Consider the following reaction: $2 HSO_{4}^{-} (a q) (1) E l ec t r o l y s i s (2) H y d r o l y s i s 2 HSO_{4}^{-} + 2 H^{+} + A$ The dihedral angle in product A in its solid phase at 110 K is :
1. A. $10 4^{\circ}$
2. B. $111. 5^{\circ}$
3. C. $90. 2^{\circ}$
4. D. $111. 0^{\circ}$
Show answer
Answer: C
Q862022 · 25 Jun 2022 · Shift 1· Numerical answer
In a cell, the following reactions take place $Fe^{2 +} \to Fe^{3 +} + e^{-} E_{Fe^{3 +} / Fe^{2 +}}^{\circ} = 0.77 V$ $2 I^{-} \to I_{2} + 2 e^{-} E_{I_{2} / I^{-}}^{\circ} = 0.54 V$ The standard electrode potential for the spontaneous reaction in the cell is $x \times 1 0^{- 2} V$ at $298 K$ . The value of $x$ is . (Nearest Integer)
Show answer
Answer: 23
Q772022 · 25 Jun 2022 · Shift 2
Given below are two statements. Statement I : During electrolytic refining, blister copper deposits precious metals. Statement II : In the process of obtaining pure copper by electrolysis method, copper blister is used to make the anode. In the light of the above statements, choose the correct from the options given below.
1. A.Both Statement I and Statement II are true.
2. B.Both Statement I and Statement II are false.
3. C.Statement I is true but Statement II is false.
4. D.Statement I is false but Statement II is true.
Show answer
Answer: A
Q832022 · 24 Jun 2022 · Shift 2· Numerical answer
The resistance of a conductivity cell containing $0.01 M KCl$ solution at $298 K$ is $1750 Ω$ . If the conductivity of $0.01 M KCl$ solution at $298 K$ is $0.152 \times 1 0^{- 3} S cm^{- 1}$ , then the cell constant of the conductivity cell is $\times 1 0^{- 3} cm^{- 1}$ .
Show answer
Answer: 266