Electrochemistry Test

Result

Electrochemistry Test - 4

Score
-
out of -
Rank
-
out of -

TIME Taken - -

SHARING IS CARING

If our Website helped you a little, then kindly spread our voice using Social Networks. Spread our word to your readers, friends, teachers, students & all those close ones who deserve to know what you know now.

Weekly Quiz Competition

Question 1
1 / -0

Zinc/Silver oxide cell is used in electric watches.

Zn → Zn²⁺ + 2e^-E⁰ = - 0.76 V

Ag₂O + H₂O + 2e^- → 2Ag + 2OH^-E⁰ cell = 0.8 V

ΔG⁰ for the reaction is

A
- 1.30 × 10⁶ J

B
- 3.01 × 10⁵ J

C
3.01 × 10⁷ J

D
1.30 × 10⁶ J

Solution

E^o = 0.8 - (- 0.76) = 1.56 V
ΔG^o = - nFE^o = - 2 × 96,500 × 1.56
ΔG^o = - 3,01,080 CV = - 3.01 ×10⁵ J (1 CV = 1 J)
Question 2
1 / -0

The unit of conductance is

A
Ω

B
Ω^-1

C
Ω^-1cm^-1

D
Ω^-1cm^-2 mol^-1

Solution

Conductance is the degree to which an object conducts electricity. It is calculated as the ratio of the current which flows to the potential difference present. This is the reciprocal of the resistance, and is measured in siemens or mhos (Ω^-1).
Question 3
1 / -0

Which of the following statements is correct?

A
The equivalent conductance of both strong and weak electrolytes decreases with dilution.

B
The equivalent conductance of strong electrolytes increases with dilution, while that of weak electrolytes decreases with dilution.

C
The equivalent conductance of strong electrolytes decreases with dilution, while that of weak electrolytes increases with dilution.

D
The equivalent conductance of both strong and weak electrolytes increases with dilution.

Solution

The equivalent conductance of both strong and weak electrolytes increases with dilution. This is because with the increase in dilution (decrease in concentration), ions become farther apart, and inter-ionic forces (i.e. forces of attraction between unlike ions and forces of repulsion between like ions) decrease considerably, so that greater number of ions are able to migrate to the electrodes. In addition, due to change in equilibrium, the electrolyte undergo further ionisation from the same mass in solution (in order to balance the effect).

Hence, more ions (conducting species) are introduced into the solution.
Question 4
1 / -0

Choose the correct statement from among the following.

A
Conductivity of platinum metal increases on heating from 0^oC to 100^oC.

B
Specific conductance of N/10 H₂SO₄ decreases with dilution.

C
Conductivity of cane sugar solution increases with dilution.

D
Aqueous NaCl is a better conductor at 50^oC than at 25^oC.

Solution

Specific conductance of H₂SO₄ decreases with dilution as the number of ions available for carrying current per unit volume decreases with dilution. Hence, option (2) is correct.

All the other statements are wrong.
Conductance of metallic conductors decreases with the rise in temperature. Hence, optrion (1) is incorrect.

Cane sugar is a non-conductor. Hence, optrion (3) is incorrect.
Conductance of electrolytic conductors increases with rise in temperature. Hence, optrion (4) is incorrect.
Question 5
1 / -0

Molar conductivity has the unit of

A
Ω^-1

B
Ω^-1 cm^-1

C
Ω^-1 cm² eq^-1

D
Ω^-1 cm² mol^-1

Solution

Molar conductivity is defined as the conductivity of an electrolyte solution divided by the molar concentration of the electrolyte and so, it measures the efficiency with which a given electrolyte conducts electricity in a solution. Its units are siemens per centimeter per molarity, or siemens centimeter - square per mole (Ω^-1 cm² mol^-1).

User

Question Analysis

Correct -
Wrong -
Skipped -

My Perfomance

Score
-
out of -
Rank
-
out of -

Re-Attempt Weekly Quiz Competition

Electrochemistry Test - 4

Result

Electrochemistry Test - 4

Score

-

Rank

-

SHARING IS CARING

Question 1

- 1.30 × 106 J

- 3.01 × 105 J

3.01 × 107 J

1.30 × 106 J

Solution

Question 2

Ω

Ω-1

Ω-1 cm-1

Ω-1 cm-2 mol-1

Solution

Question 3

The equivalent conductance of both strong and weak electrolytes decreases with dilution.

The equivalent conductance of strong electrolytes increases with dilution, while that of weak electrolytes decreases with dilution.

The equivalent conductance of strong electrolytes decreases with dilution, while that of weak electrolytes increases with dilution.

The equivalent conductance of both strong and weak electrolytes increases with dilution.

Solution

Question 4

Conductivity of platinum metal increases on heating from 0o C to 100o C.

Specific conductance of N/10 H2SO4 decreases with dilution.

Conductivity of cane sugar solution increases with dilution.

Aqueous NaCl is a better conductor at 50oC than at 25oC.

Solution

Question 5

Ω-1

Ω-1 cm-1

Ω-1 cm2 eq-1

Ω-1 cm2 mol-1

Solution

User

Question Analysis

My Perfomance

Score

-

Rank

-

Results Announcement on: coming Monday

Stay Tuned: We’ll update you on your result via email or SMS.

- 1.30 × 10⁶ J

- 3.01 × 10⁵ J

3.01 × 10⁷ J

1.30 × 10⁶ J

Ω^-1

Ω^-1cm^-1

Ω^-1cm^-2 mol^-1

Conductivity of platinum metal increases on heating from 0^oC to 100^oC.

Specific conductance of N/10 H₂SO₄ decreases with dilution.

Aqueous NaCl is a better conductor at 50^oC than at 25^oC.

Ω^-1

Ω^-1 cm^-1

Ω^-1 cm² eq^-1

Ω^-1 cm² mol^-1