Formula To Calculate Surface Tension Of Water

Surface Tension Formula:

\[ \gamma = \frac{\rho \cdot g \cdot r \cdot h}{2} \]

Surface Tension (γ):

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1. What Is Surface Tension?

Surface tension is the elastic tendency of a fluid surface which makes it acquire the least surface area possible. It is caused by the cohesive forces between liquid molecules at the surface. In water, this property allows insects to walk on water and causes capillary action.

2. How Does The Calculator Work?

The calculator uses the capillary rise method formula:

\[ \gamma = \frac{\rho \cdot g \cdot r \cdot h}{2} \]

Where:

\( \gamma \) — Surface tension (N/m)
\( \rho \) — Density of the liquid (kg/m³)
\( g \) — Acceleration due to gravity (9.8 m/s²)
\( r \) — Radius of the capillary tube (m)
\( h \) — Height of liquid rise in the capillary (m)

Explanation: This formula calculates surface tension based on the height a liquid rises in a narrow capillary tube due to capillary action.

3. Importance Of Surface Tension Calculation

Details: Surface tension measurements are important in various fields including physics, chemistry, biology, and engineering. It helps understand fluid behavior, design microfluidic devices, study biological processes, and develop industrial products like detergents and coatings.

4. Using The Calculator

Tips: Enter the density of the liquid in kg/m³ (for water at 20°C, use 998 kg/m³), the radius of the capillary tube in meters, and the height of liquid rise in meters. All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What is the typical surface tension of water?
A: At 20°C, the surface tension of water is approximately 0.0728 N/m.

Q2: How does temperature affect surface tension?
A: Surface tension generally decreases with increasing temperature as molecular kinetic energy increases.

Q3: What factors can alter surface tension?
A: Temperature, dissolved substances (especially surfactants), and impurities can significantly affect surface tension.

Q4: Why is the capillary method used for measuring surface tension?
A: The capillary rise method is simple, relatively accurate, and doesn't require complex equipment compared to other methods.

Q5: What are some practical applications of surface tension?
A: Surface tension is crucial in processes like inkjet printing, pharmaceutical formulations, emulsion stability, and the functioning of lung surfactants.