Activity Coefficient of Cathodic Electrolyte of Concentration Cell without Transference Calculator

Formula Used:

\[ \gamma_2 = \exp\left(\frac{E_{cell} \cdot F}{2 \cdot R \cdot T}\right) \cdot \left(\frac{m_1 \cdot \gamma_1}{M_2}\right) \]

EMF of Cell (Volts):

Temperature (K):

Anodic Electrolyte Molality:

mol/kg

Anodic Activity Coefficient:

Cathodic Electrolyte Molality:

mol/kg

Cathodic Activity Coefficient (γ₂):

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1. What is Cathodic Activity Coefficient?

Definition: The Cathodic Activity Coefficient is a factor used in thermodynamics to account for deviations from ideal behavior in a mixture of chemical substances in the cathodic half cell.

Purpose: It helps quantify how the chemical potential of a substance in a mixture differs from its ideal behavior.

2. How Does the Calculator Work?

The calculator uses the formula:

\[ \gamma_2 = \exp\left(\frac{E_{cell} \cdot F}{2 \cdot R \cdot T}\right) \cdot \left(\frac{m_1 \cdot \gamma_1}{M_2}\right) \]

Where:

\( \gamma_2 \) — Cathodic Activity Coefficient
\( E_{cell} \) — EMF of the cell (Volts)
\( F \) — Faraday constant (96485.33212 C/mol)
\( R \) — Universal gas constant (8.314 J/(mol·K))
\( T \) — Temperature (Kelvin)
\( m_1 \) — Anodic Electrolyte Molality (mol/kg)
\( \gamma_1 \) — Anodic Activity Coefficient
\( M_2 \) — Cathodic Electrolyte Molality (mol/kg)

3. Importance of Activity Coefficients

Details: Activity coefficients are crucial for accurate thermodynamic calculations in electrochemical systems, especially when dealing with non-ideal solutions.

4. Using the Calculator

Tips: Enter all required values (EMF, temperature, molalities, and anodic coefficient). Temperature must be in Kelvin. All values must be positive.

5. Frequently Asked Questions (FAQ)

Q1: What is a typical value for activity coefficients?
A: For ideal solutions, γ ≈ 1. For non-ideal solutions, γ can be less than 1 (negative deviation) or greater than 1 (positive deviation).

Q2: Why is temperature important in this calculation?
A: Temperature affects the exponential term in the Nernst equation, which is part of this calculation.

Q3: What units should I use for molality?
A: Molality should be in moles of solute per kilogram of solvent (mol/kg).

Q4: How accurate is this calculation?
A: The calculation is theoretically accurate for ideal conditions, but real systems may show deviations.

Q5: Can I use molarity instead of molality?
A: No, molality is preferred because it doesn't change with temperature (unlike molarity which depends on solution volume).