Chemistry Exam  >  Chemistry Questions  >  The cell potential for the following electroc... Start Learning for Free
The cell potential for the following electrochemical system at 25°C is:
Al(s) | Al3+ (0.01 M) || Fe2+ (0.1 M) | Fe (s)
Given: Standard reduction potential of Al3+ + 3e → Al is –1.66 V at 25°C
Standard reduction potential of Fe2+ + 2e → Fe is –0.44 V at 25°C
  • a)
    1.23 V
  • b)
    1.21 V
  • c)
    1.22 V
  • d)
    –2.10 V
Correct answer is option 'A'. Can you explain this answer?
Most Upvoted Answer
The cell potential for the following electrochemical system at 25°...
Solution:

The cell potential (Ecell) of an electrochemical cell is given by the difference between the standard reduction potentials of the half-cells.

Ecell = E°(reduction at cathode) - E°(reduction at anode)

Given: E°(Al3+ + 3e- → Al) = 1.66 V
E°(Fe2+ + 2e- → Fe) = 0.44 V

We need to determine the cell potential for the following electrochemical system at 25C:

Al(s) | Al3+ (0.01 M) || Fe2+ (0.1 M) | Fe(s)

The cell diagram represents the two half-cells in the electrochemical cell. The two vertical lines represent the phase boundary between the two half-cells, and the double vertical line represents the salt bridge.

The half-cell reactions for the given electrochemical system are:

Al3+ + 3e- → Al (reduction at cathode)
Fe2+ → Fe + 2e- (oxidation at anode)

Step 1: Write the balanced cell reaction:

Al(s) + Fe2+ (0.1 M) → Al3+ (0.01 M) + Fe(s)

Step 2: Determine the reduction potential for the cathode:

E°(Al3+ + 3e- → Al) = 1.66 V

Step 3: Determine the oxidation potential for the anode:

E°(Fe2+ → Fe + 2e-) = -0.44 V (Note: The oxidation potential is the negative of the reduction potential.)

Step 4: Calculate the cell potential:

Ecell = E°(reduction at cathode) - E°(reduction at anode)
Ecell = 1.66 V - (-0.44 V)
Ecell = 2.10 V

However, this value is incorrect as the reduction potential for iron in the given electrochemical system is not standard. We need to use the Nernst equation to calculate the actual cell potential.

Step 5: Calculate the actual cell potential using the Nernst equation:

Ecell = E° - (RT/nF) ln(Q)

where,
E° = standard cell potential
R = gas constant = 8.314 J/mol K
T = temperature in Kelvin
n = number of electrons transferred
F = Faraday constant = 96,485 C/mol
Q = reaction quotient

At equilibrium, Q = K, the equilibrium constant.

K = [Al3+] / [Fe2+]

At 25°C, the equilibrium constant for the reaction is:

K = [Al3+] / [Fe2+]
K = (0.01 M) / (0.1 M)
K = 0.1

Substituting the values in the Nernst equation:

Ecell = E° - (RT/nF) ln(Q)
Ecell = 1.66 V - (0.0257 V) ln(0.1)
Ecell = 1.23 V

Therefore, the cell potential for the given electrochemical system at 25°C is 1.23 V.

Answer: Option (a) 1.23 V.
Free Test
Community Answer
The cell potential for the following electrochemical system at 25°...
Explore Courses for Chemistry exam
The cell potential for the following electrochemical system at 25°C is:Al(s) | Al3+ (0.01 M) || Fe2+ (0.1 M) | Fe (s)Given: Standard reduction potential of Al3+ + 3e– → Al is –1.66 V at 25°CStandard reduction potential of Fe2+ + 2e– → Fe is –0.44 V at 25°Ca)1.23 Vb)1.21 Vc)1.22 Vd)–2.10 VCorrect answer is option 'A'. Can you explain this answer?
Question Description
The cell potential for the following electrochemical system at 25°C is:Al(s) | Al3+ (0.01 M) || Fe2+ (0.1 M) | Fe (s)Given: Standard reduction potential of Al3+ + 3e– → Al is –1.66 V at 25°CStandard reduction potential of Fe2+ + 2e– → Fe is –0.44 V at 25°Ca)1.23 Vb)1.21 Vc)1.22 Vd)–2.10 VCorrect answer is option 'A'. Can you explain this answer? for Chemistry 2024 is part of Chemistry preparation. The Question and answers have been prepared according to the Chemistry exam syllabus. Information about The cell potential for the following electrochemical system at 25°C is:Al(s) | Al3+ (0.01 M) || Fe2+ (0.1 M) | Fe (s)Given: Standard reduction potential of Al3+ + 3e– → Al is –1.66 V at 25°CStandard reduction potential of Fe2+ + 2e– → Fe is –0.44 V at 25°Ca)1.23 Vb)1.21 Vc)1.22 Vd)–2.10 VCorrect answer is option 'A'. Can you explain this answer? covers all topics & solutions for Chemistry 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for The cell potential for the following electrochemical system at 25°C is:Al(s) | Al3+ (0.01 M) || Fe2+ (0.1 M) | Fe (s)Given: Standard reduction potential of Al3+ + 3e– → Al is –1.66 V at 25°CStandard reduction potential of Fe2+ + 2e– → Fe is –0.44 V at 25°Ca)1.23 Vb)1.21 Vc)1.22 Vd)–2.10 VCorrect answer is option 'A'. Can you explain this answer?.
Solutions for The cell potential for the following electrochemical system at 25°C is:Al(s) | Al3+ (0.01 M) || Fe2+ (0.1 M) | Fe (s)Given: Standard reduction potential of Al3+ + 3e– → Al is –1.66 V at 25°CStandard reduction potential of Fe2+ + 2e– → Fe is –0.44 V at 25°Ca)1.23 Vb)1.21 Vc)1.22 Vd)–2.10 VCorrect answer is option 'A'. Can you explain this answer? in English & in Hindi are available as part of our courses for Chemistry. Download more important topics, notes, lectures and mock test series for Chemistry Exam by signing up for free.
Here you can find the meaning of The cell potential for the following electrochemical system at 25°C is:Al(s) | Al3+ (0.01 M) || Fe2+ (0.1 M) | Fe (s)Given: Standard reduction potential of Al3+ + 3e– → Al is –1.66 V at 25°CStandard reduction potential of Fe2+ + 2e– → Fe is –0.44 V at 25°Ca)1.23 Vb)1.21 Vc)1.22 Vd)–2.10 VCorrect answer is option 'A'. Can you explain this answer? defined & explained in the simplest way possible. Besides giving the explanation of The cell potential for the following electrochemical system at 25°C is:Al(s) | Al3+ (0.01 M) || Fe2+ (0.1 M) | Fe (s)Given: Standard reduction potential of Al3+ + 3e– → Al is –1.66 V at 25°CStandard reduction potential of Fe2+ + 2e– → Fe is –0.44 V at 25°Ca)1.23 Vb)1.21 Vc)1.22 Vd)–2.10 VCorrect answer is option 'A'. Can you explain this answer?, a detailed solution for The cell potential for the following electrochemical system at 25°C is:Al(s) | Al3+ (0.01 M) || Fe2+ (0.1 M) | Fe (s)Given: Standard reduction potential of Al3+ + 3e– → Al is –1.66 V at 25°CStandard reduction potential of Fe2+ + 2e– → Fe is –0.44 V at 25°Ca)1.23 Vb)1.21 Vc)1.22 Vd)–2.10 VCorrect answer is option 'A'. Can you explain this answer? has been provided alongside types of The cell potential for the following electrochemical system at 25°C is:Al(s) | Al3+ (0.01 M) || Fe2+ (0.1 M) | Fe (s)Given: Standard reduction potential of Al3+ + 3e– → Al is –1.66 V at 25°CStandard reduction potential of Fe2+ + 2e– → Fe is –0.44 V at 25°Ca)1.23 Vb)1.21 Vc)1.22 Vd)–2.10 VCorrect answer is option 'A'. Can you explain this answer? theory, EduRev gives you an ample number of questions to practice The cell potential for the following electrochemical system at 25°C is:Al(s) | Al3+ (0.01 M) || Fe2+ (0.1 M) | Fe (s)Given: Standard reduction potential of Al3+ + 3e– → Al is –1.66 V at 25°CStandard reduction potential of Fe2+ + 2e– → Fe is –0.44 V at 25°Ca)1.23 Vb)1.21 Vc)1.22 Vd)–2.10 VCorrect answer is option 'A'. Can you explain this answer? tests, examples and also practice Chemistry tests.
Explore Courses for Chemistry exam
Signup for Free!
Signup to see your scores go up within 7 days! Learn & Practice with 1000+ FREE Notes, Videos & Tests.
10M+ students study on EduRev