Question

Number of coulombs corresponding to 1 mol of electrons approximately is equal to

• A. \(1.93 \times 10^5\)
• B. \(9.65 \times 10^4\)
• C. \(1.93 \times 10^4\)
• D. \(9.65 \times 10^5\)

Hint:

The value of the Faraday constant, approximately 96500 C/mol, is one of the most important constants in electrochemistry.
It is essential to memorize this value for quick calculations in electrolysis and electrochemical cell problems.

Answer 1

The Correct Option is B

Step 1: Understanding the Question:
This question asks for the value of the total charge carried by one mole of electrons.
This quantity is a fundamental constant in chemistry and physics known as the Faraday constant (F).

Step 2: Key Formula or Approach:
The Faraday constant is calculated by multiplying the charge of a single electron (the elementary charge, \(e\)) by Avogadro's number (\(N_A\)).
\[ F = e \times N_A \]

Step 3: Detailed Explanation:
The standard values for the constants are:
- Charge of one electron, \(e \approx 1.602 \times 10^{-19}\) Coulombs (C).
- Avogadro's number, \(N_A \approx 6.022 \times 10^{23}\) mol\(^{-1}\).
Now, we calculate the Faraday constant:
\[ F = (1.602 \times 10^{-19} \text{ C}) \times (6.022 \times 10^{23} \text{ mol}^{-1}) \]
\[ F \approx 9.6485 \times 10^4 \text{ C/mol} \]
This value is commonly approximated for calculations as 96500 C/mol.
Writing this approximation in scientific notation gives:
\[ 96500 = 9.65 \times 10^4 \]
This matches option (B).

Step 4: Final Answer:
The number of coulombs corresponding to 1 mole of electrons is approximately \(9.65 \times 10^4\).