Selectivity of Solute based on Activity Coefficients Calculator

Selectivity Formula:

\[ \beta_{C,A} = \frac{\gamma_{CR}/\gamma_{CE}}{\gamma_{AR}/\gamma_{AE}} \]

Activity Coefficient of Solute in Raffinate (γ_CR):

Activity Coefficient of Solute in Extract (γ_CE):

Activity Coefficient of Carrier in Raffinate (γ_AR):

Activity Coefficient of Carrier in Extract (γ_AE):

Selectivity (β_C,A):

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1. What is Selectivity based on Activity Coefficients?

Definition: Selectivity or Separation Factor is defined as the preferential uptake of the solute by the solvent over the carrier in liquid-liquid extraction processes.

Purpose: This calculator determines the selectivity using activity coefficients of components in both raffinate and extract phases.

2. How Does the Calculator Work?

The calculator uses the formula:

\[ \beta_{C,A} = \frac{\gamma_{CR}/\gamma_{CE}}{\gamma_{AR}/\gamma_{AE}} \]

Where:

\( \beta_{C,A} \) — Selectivity or separation factor
\( \gamma_{CR} \) — Activity coefficient of solute in raffinate
\( \gamma_{CE} \) — Activity coefficient of solute in extract
\( \gamma_{AR} \) — Activity coefficient of carrier in raffinate
\( \gamma_{AE} \) — Activity coefficient of carrier in extract

Explanation: The formula compares the relative distribution of solute versus carrier between the two phases.

3. Importance of Selectivity Calculation

Details: Selectivity determines the efficiency of separation in liquid-liquid extraction processes. Higher values indicate better separation.

4. Using the Calculator

Tips: Enter all four activity coefficients (must be > 0). The calculator will compute the selectivity factor.

5. Frequently Asked Questions (FAQ)

Q1: What does a selectivity value of 1 mean?
A: A value of 1 means no separation occurs between solute and carrier.

Q2: What's considered a good selectivity value?
A: Values significantly greater than 1 (typically >2) indicate effective separation.

Q3: How are activity coefficients determined?
A: They can be obtained from experimental data or thermodynamic models like UNIQUAC or NRTL.

Q4: Does temperature affect selectivity?
A: Yes, temperature impacts activity coefficients and thus affects selectivity.

Q5: What if I get a selectivity less than 1?
A: This indicates the carrier is preferentially extracted over the solute - consider changing solvents.