Electrochemistry

Question 1

Conductivity order NCERT TABLE

Answer 1

1. Silver:
   
   2. Copper:
   3. Gold:
   4. Sodium:
   5. Iron:
   6. Graphite:
   7. 0.1 M HCl
   8. Ge (Semiconductor):
   9. Si (Semiconductor):
   10. 0.01 M KCl (Aqueous solution):
   11. 0.01 M NaCl (Aqueous solution):
   12. 0.1 M HAc (Aqueous solution):
   13. 0.01 M HAc (Aqueous solution):
   14. CuO (Semiconductor):
   15. Pure Water (Aqueous solution):
   16. Glass (Insulator):
   17. Teflon (Insulator):

Question 2

conductivity of electrolytic (ionic)
solutions depends on:
6 factors

Answer 2

(i) the nature of the electrolyte added
(ii) size of the ions produced
(iii) the nature of the solvent and its viscosity
(iv) concentration of the electrolyte
(v) temperature (it increases with the increase of temperature).
(vi) solvation of ions

Question 3

If reduction potential of metal ion is greater then O2/H2O couple, the ion is………

Answer 3

stable in water.

Question 4

Coulometer (a standard electrolytic
cell) is used for…………

Answer 4

for determining the quantity of electricity passed from the amount
of metal (generally silver or copper) deposited or consumed.

Question 5

Statement 1: If the electrode is
inert (platinum or gold) it does not participate in the chemical
reaction and acts only as source or sink for electrons.
Statement 2: Some of the electrochemical processes
although feasible, are so slow kinetically that at lower voltages these do not seem to take place and extra potential (called overpotential) be applied, which makes such process more difficult to occur.

Answer 5

Both statements are true

Question 6

Statement 1: Nowadays a number of ceramic materials and mixed oxides are also known to show
superconductivity at temperatures as high as 150 K.
Statement 2: Very pure water has small amounts of
hydrogen and hydroxyl ions (~10–7M) which lend it very low conductivity
3.5 × 10–5 S m–1

Answer 6

Both statements are correct

Question 7

Conductivity of electrolytic (ionic)
solutions depends on: 5 factors

Answer 7

(i) the nature of the electrolyte added
(ii) size of the ions produced and their solvation
(iii) the nature of the solvent and its viscosity
(iv) concentration of the electrolyte
(v) temperature (it increases with the increase of temperature)

Question 8

Measuring the resistance
of an ionic solution we face two problems.

Answer 8

Firstly, passing direct current
(DC) changes the composition of the solution.
Secondly, a solution cannot
be connected to the bridge like a metallic wire or other solid conductor.

Question 9

Assertion Difficulty in measuring resistance of electrolyte solutions can be solved.
Reason: The first difficulty is resolved by using an alternating current (AC) source
of power. The second problem is solved by using a specially designed
vessel called conductivity cell.

Answer 9

Both assertion and reason are correct and R is correct explanation of A

Question 10

Discharge potential may be defined as…….

Answer 10

Minimum potential applied in order to bring about electrolysis

Question 11

Assertion: NaCl, CaCl2, MgSO4 are known as 1-1, 2-1 and 2-2
electrolytes respectively.
Reason: The value of the constant ‘A’ for a given solvent and
temperature depends on the type of electrolyte i.e., the charges on the
cation and anion produced on the dissociation of the electrolyte in the
solution.

Answer 11

Both are correct