Chemistry Class 12 Chapter 3

1. A standard hydrogen electrode that a zero potential because ……………..

(a) hydrogen can be most’easily oxidized

(b) hydrogen has only one electron

(c) the electrode potential is assumed to be zero

(d) hydrogen is the lightest element.

Ans (C)

2. Which of the following is the correct order in which metals displace each other from the salt solution of their salts  ?

(a) Zn, Al, Mg, Fe, Cu

(b) Cu, Fe, Mg, Al, Zn

(c) Mg, Al, Zn, Fe, Cu

(d) Al, Mg, Fe, Cu, Zn

Ans (D)

3. Fluorine is the best oxidising agent because it has ………..

(a) highest electron affinity

(b) highest reduction potential

(c) highest oxidation potential

(d) lowest electron affinity.

Ans (B)

4. The molar conductivity is maximum for the solution of concentration

(a) 0.004 M

(b) 0.002 M

(c) 0.005 M

(d) 0.001 M

Ans (D)

5. Specific conductance of 0.1 M NaCl solution is 1.01 x 10^-2 ohm^-1cm^-1. Its molar conductance in ohm^-1 cm² mol^-1

(a) 1.01 x 10²

(b) 1.01 x 10³

(c) 1.01 x 10⁴

(d) 1.01

Ans (A)

6. When water is added to an aqueous solution of an electrolyte, what is the change in specific conductivity of the electrolyte ?

(a) Conductivity decreases

(b) Conductivity increases

(c) Conductivity remain same

(d) Conductivity does not depend on number of ions

Ans (A)

7. In galvanic cell, anode is : 

(a) Negative electrode

(b) Positive electrode 

(c) Neutral electrode

(d) None of these

Ans (A)

8. The cell which involves the conversion of chemical energy into electrical energy is called : 

(a) Electrolytic cell

(b) Galvanic cell 

(c) Conductivity cell

(d) All of these

Ans (B)

9. When flow of electric current in a conductor is through flow of electron then, the conductor is called:

(a) Metallic conductor

(b) Electrolytic conductor

(c) Bad conductor 

(d) None of these

Ans (A)

10. If  96500 coulomb electricity is passed through CuSO₄Solution, it will liberate. 

(a) 63.5 gm of Cu

(b) 31.76 gm of Cu 

(c) 96500 gm of Cu

(d) 100 gm of Cu

Ans (B)

11. Fused NaCl on electrolysis gives …… on cathode. 

(a) Chlorine 

(b) Sodium

(c) Sodium amalgam

(d) Hydrogen

Ans (B)

12. In an aqueous solution hydrogen (H) will not reduce : 

(a) Fe³⁺

(b) Zn²⁺ 

(c) Cu²⁺ 

(d) Ag 

Ans (A)

13. Which of the following is a secondary cell ? 

(a) Leclanche cell 

(b) Lead storage battery

(c) Concentration cell

(d) All of these

Ans (B)

14. Faraday’s second law of electrolysis is related to : 

(a) Atomic number of cation

(b) Speed of cation

(c) Speed of anion

(d) Equivalent weight of electrolyte 

Ans (D)

15. The molar conductivity is maximum for the solution of concentration :

(a) 0.004 M 

(b) 0.002 M

(c) 0.005 M 

(d) 0.001 M

Ans (D)

16. Which has the maximum standard oxidation potential ? 

(a) Zn 

(b) Cu 

(c) Ag

(d) Mg 

Ans (D)

17. The quantity of charge required to obtain one mole of aluminium from Al₂O₃is …….

(a) 1 F 

(b) 6 F

(c) 3 F 

(d) 2 F 

Ans (C)

18. One Faraday electricity equal to how much Coulombs ?

(a) 96550 

(b) 96500

(c) 96000 

(d) 95500

Ans (B)

19. When one faraday of electric current is passed, the mass deposited, is equal to : 

(a) One gram equivalent

(b) One gram mole

(c) electrochemical equivalent

(d) Half gram equivalent 

Ans (C)

20. The electrode through which electrons enter into electrolytic solution is: 

(a) Cathode 

(b) Anode

(c) May be anode cathode

(d) None 

Ans (C)

21. A dilute aqueous solution of sodium fluoride is electrolysed, the products at the anode and cathode are : 

(a) F, Na 

(b) F₂, H₂ 

(c) O₂ , Na 

(d) O₂, H₂

Ans (B)