Electrochemistry MCQs- Class 12

All About Chemistry4 years ago2 weeks ago01 mins

This question paper consists of 20 MCQ questions. 20 Marks.

1. The resistivity of 0.8 M solution of an electrolyte is 5 × 10-3 Ω cm. Calculate the molar conductivity of the solution. 0.75 ×10^6 0.25 ×10^6 0.95 ×10^6 0.15 ×10^6

2. Conductivity of a decinormal solution of KCl is 0.0112 Ω-1cm-1. The resistance of the cell containing the solution is 55 Ω. calculate the cell constant. 0.616 0.82 0.112 0.543

3.The resistance of 0.01 N solution of an electrolyte is 210 Ω. Calculate the equivalent conductivity of the solution if the cell constant is 0.88 cm-1. 555 234 987 419

4. 2Ag^+ + Cd→2Ag + Cd^2+. Calculate the standard cell emf(E^o) . Will be the total emf be more +ve or –ve if the concentration of Cd^2+ is 0.10M rather than 1M.[E^o Ag+/Ag =0.80V and Cd^2+/Cd = -0.40V] 3.5V, -ve 2.5V, +ve 1.2V, +ve 3.5V, -ve

5. Copper is electrodeposited by using Cu2Cl2 solution on metallic vessel of surface are 400 cm2 by passing a current of 0.2 A for 3 hours. Calculate the thickness of copper deposited. [Cu=63.6, Density of copper= 8.9 g/mL] 5 x 10^-4 cm 4 x 10^-4 cm 4 x 10^-2 cm 6 x 10^-6 cm

6.Resistance of a conductivity cell filled with 0.1 mol /L KCl solution is 100 Ω. If the resistance of the same cell when filled with 0.02 mol /L KCl is 520 Ω calculate the conductivity and molar conductivity of 0.02 M KCl solution. The conductivity of 0.1 M KCl solution is 1.29 Ω-1m-1. 0.00248 Ω-1 cm -1, 124 Ω-1 cm 2 mol -1 0.00345 Ω-1 cm -1, 124 Ω-1 cm 2 mol -1 0.00248 Ω-1 cm -1, 762 Ω-1 cm 2 mol -1 0.00678 Ω-1 cm -1, 724 Ω-1 cm 2 mol -1

7.How long will it take for a uniform current of 6 A to deposit 78g Gold from a solution of AuCl4-? What mass of chlorine gas will be formed simultaneously at the anode of the electrolytic cell? 2914sec, 72.16g 4914sec, 22.16g 5614sec, 12.16g 1914sec, 42.16g

8.A graph is plotted between Ecell and log[Zn2+]/[Cu2+]. The curve was linear with intercept on Ecell axis equal to 1.10V. Calculate Ecell for : Zn|Zn2+(0.1M)||Cu2+(0.01M)|Cu. 1.0705V 3.097V 4.987V 9.765V

9. After electrolysis of a sodium chloride solution with inert electrodes for a certain period of time, 600 mL of the 1N solution was left which was found to be NaOH. During the same time 31.08g of Cu was deposited in Copper voltameter in series with the electrolytic cell. Calculate the % of NaOH obtained.[Cu=63.6] 40% 60% 10% 90%

10.Resistance of a conductivity cell filled with 0.1 mol L-1KCl solution is 100 Ω. If the resistance of the same cell when filled with 0.02 mol L-1 KCl solution is 520 Ω, calculate the conductivity and molar conductivity of 0.02 M KCl solution. The conductivity of 0.1 M KCl solution is 1.29 Ω-1m-1. 0.0924 Ω-1m2mol-1 0.0724 Ω-1m2mol-1 0.0124 Ω-1m2mol-1 0.0524 Ω-1m2mol-1

11.The electrical resistance of a column of 0.05 M NaOH solution of diameter 1 cm and length 50 cm is 5.55 ×10^3 Ω. Calculate its resistivity, conductivity and molar conductivity. 87.135 Ω cm, 0.01148 Ω-1 cm -1, 229.6 Ω-1 cm 2 mol -1 17.135 Ω cm, 0.05148 Ω-1 cm -1, 729.6 Ω-1 cm 2 mol -1 37.135 Ω cm, 0.06148 Ω-1 cm -1, 629.6 Ω-1 cm 2 mol -1 47.135 Ω cm, 0.04148 Ω-1 cm -1, 429.6 Ω-1 cm 2 mol -1

12. The resistance of 0.02 M KCl and 0.05 M AgNO3 solution in a given conductivity cell is 164 Ω and 78.5 Ω respectively. If conductivity of 0.02 M KCl solution is 2.768 ×10^-3 Ω-1cm-1, then calculate the molar conductivity of 0.05 M AgNO3 solution.. 715.6 Ω-1 cm 2 mol -1 515.6 Ω-1 cm 2 mol -1 315.6 Ω-1 cm 2 mol -1 115.6 Ω-1 cm 2 mol -1

13.Calculate the EMF of the cell containing chromium and cadmium electrodes. (EoCr3+/Cr = -0.74V, EoCd2+/Cd = -0.40V) 0.45V 0.34V 0.95V 0.21V

14.Given molar conductivities at infinite dilution of Ba(OH)2, BaCl2, NH4Cl are 457.6,240.6,129.8 Ω-1cm2mol-1 respectively. Determine λo for NH4OH. 638.3 Ω-1 cm 2 mol -1 438.3 Ω-1 cm 2 mol -1 238.3 Ω-1 cm 2 mol -1 138.3 Ω-1 cm 2 mol -1

15.Calculate the molar ionic conductance of Al3+ ions at infinite dilution, the molar conductivities at infinite dilution of Al2(SO4)3 and molar inic conductance of SO42- ions are 858 and 160 Ω-1cm2mol-1 respectively. 981 Ω-1 cm 2 mol -1 654 Ω-1 cm 2 mol -1 239 Ω-1 cm 2 mol -1 189 Ω-1 cm 2 mol -1

16. The specific conductance of a saturated solution of AgCl in water is 1.826 × 10-6 Ω-1 cm -1 . Calculate the solubility in water when λo Ag+ = 61.92 and Cl- = 76.34 Ω-1 cm 2 mol -1 respectively. 1.32 ×10-5 mol/L 2.32 ×10-5 mol/L 3.32 ×10-5 mol/L 4.32 ×10-5 mol/L

17.The conductivities of 0.001028 M acetic acid is 4.95 ×10-5 Ω-1 cm -1 . Calculate its dissociation constant if λo for acetic acid is 390.5 Ω-1cm2mol-1. 2.78 ×10-5 mol/L 1.78 ×10-5 mol/L 3.78 ×10-5 mol/L 5.78 ×10-5 mol/L

18.If the molar conductivities at infinite dilution at 293 K for aqueous HCl, CH3COONa and NaCl solution are 383.5, 78.4 and 102.0 Ω-1cm2mol-1 respectively, calculate the molar conductivity of acetic acid at this temperature and dilution. If the molar conductivity of acetic acid at some other dilution is 100 Ω-1cm2mol-1 , calculate the degree of ionization of acetic acid at this dilution. 559.9 Ω-1 cm 2 mol -1, 0.478 459.9 Ω-1 cm 2 mol -1, 0.378 359.9 Ω-1 cm 2 mol -1, 0.278 259.9 Ω-1 cm 2 mol -1, 0.178

19. The EMF of the following cell is found to be 0.20V at 298K. Cd|Cd2+||Ni2+(2M)||Ni. What is the molar concentration of Cd2+ ions in the solution? (EoCd+/Cd= -0.40V, Ni2+/Ni = -0.25V) 0.0409M 0.0111M 0.0204M 0.0909M

20.Calculate the standard electrode potential of Ni+2/Ni if E.M.F. of the cell Ni/Ni+2(0.01M)//Cu+2(0.1M)/Cu; Ecell = 0.59 V and Eo Cu /Cu 2+ = 0.34 V . -0.11V -0.22V -0.02V -0.0022V

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