1. What is Parachor?

Definition: Parachor is a physical quantity that relates surface tension to molecular structure and is used to predict properties of liquids.

Purpose: It helps in understanding molecular interactions and predicting surface tension of liquids based on their composition.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( P_s \) — Parachor (m³/mol·(N/m)^0.25)
• \( M_{molar} \) — Molar mass (kg/mol)
• \( \rho_{liq} \) — Density of liquid (kg/m³)
• \( \rho_v \) — Density of vapor (kg/m³)
• \( \gamma \) — Surface tension (N/m)

Explanation: The formula relates the molecular properties to surface tension through dimensional analysis.

3. Importance of Parachor Calculation

Details: Parachor values are useful in chemical engineering for predicting surface tension, studying molecular structure, and designing industrial processes.

4. Using the Calculator

Tips: Enter the molar mass, liquid density, vapor density (default 0.5 kg/m³), and surface tension (default 0.073 N/m for water at 20°C). All values must be positive except vapor density which can be zero.

5. Frequently Asked Questions (FAQ)

Q1: What are typical Parachor values?
A: Parachor values typically range from 1×10⁻⁵ to 1×10⁻⁴ m³/mol·(N/m)^0.25 depending on the substance.

Q2: Why is the exponent 1/4 used in the formula?
A: The exponent comes from dimensional analysis that relates surface tension to molecular volume.

Q3: When can vapor density be neglected?
A: For most liquids at normal conditions, vapor density is much smaller than liquid density and can often be approximated as zero.

Q4: What are common surface tension values?
A: Water at 20°C has 0.073 N/m, mercury 0.487 N/m, and ethanol 0.022 N/m.

Q5: How is molar mass determined?
A: Molar mass is the sum of atomic masses of all atoms in a molecule, available from chemical formulas and periodic tables.