Surface Tension given Molecular Weight Calculator

Surface Tension Formula:

\[ γ = \frac{[EOTVOS\_C] \times (T_c - T - 6)}{(\frac{MW}{ρ_{liq}})^{\frac{2}{3}}} \]

Critical Temperature (T_c):

Temperature (T):

Molecular Weight (MW):

Density of Liquid (ρ_liq):

kg/m³

Surface Tension (γ):

N/m

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1. What is Surface Tension given Molecular Weight Calculator?

Definition: This calculator estimates the surface tension of a fluid based on the Eötvös rule, using critical temperature, current temperature, molecular weight, and liquid density.

Purpose: It helps researchers and engineers determine the surface tension of liquids when molecular properties are known.

2. How Does the Calculator Work?

The calculator uses the Eötvös formula:

\[ γ = \frac{[EOTVOS\_C] \times (T_c - T - 6)}{(\frac{MW}{ρ_{liq}})^{\frac{2}{3}}} \]

Where:

\( γ \) — Surface tension of fluid (N/m)
\( [EOTVOS\_C] \) — Eötvös constant (2.1 × 10⁻⁷)
\( T_c \) — Critical temperature (K)
\( T \) — Temperature (K)
\( MW \) — Molecular weight (kg)
\( ρ_{liq} \) — Density of liquid (kg/m³)

Explanation: The formula relates surface tension to the temperature difference from critical point and the molar volume of the liquid.

3. Importance of Surface Tension Calculation

Details: Surface tension affects capillary action, wetting, detergency, and is crucial in many industrial processes and biological systems.

4. Using the Calculator

Tips: Enter the critical temperature, current temperature (both in Kelvin), molecular weight in kg, and liquid density in kg/m³. All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What is the Eötvös constant?
A: It's an empirical constant (2.1 × 10⁻⁷ J/K·mol²/³) that appears in the Eötvös rule for surface tension.

Q2: How accurate is this calculation?
A: The Eötvös rule gives approximate values and works best for simple, non-associated liquids.

Q3: Where can I find critical temperature values?
A: Critical temperatures are tabulated in chemical data handbooks for many substances.

Q4: Why is there a -6 in the formula?
A: This is an empirical correction factor in the Eötvös equation to improve accuracy.

Q5: What are typical surface tension values?
A: Water at 20°C has γ ≈ 0.0728 N/m, while organic liquids typically range from 0.02 to 0.05 N/m.