This document discusses surface tension and methods to measure it. Surface tension is defined as the tension of a liquid's surface caused by particle attraction in the surface layer minimizing surface area. Interfacial tension is the force per unit length at an interface countering inward pull. Factors like temperature, solute concentration, and intermolecular forces affect surface tension. Common measurement methods include the capillary rise, drop weight, bubble pressure, and Wilhelmy plate methods. Surface tension can override principles like Archimedes' law by allowing objects denser than water to float.

1. METAMORPHIC PETROLOGY PPT INSTRUCTED BY P.S. SIR

2. 1. INTRODUCTION
2.SURFACE TENSION & INTERFACIAL TENSION
3. EXAMPLE OF SURFACE TENSION
4. FACTOR AFFECTING SURFACE TENSION
5. MESUREMENT OF SURFACE AND INTERFACIAL TENSION
6.CONCLUSION
7. REFERENCE

3. Agnes Pockels, a self-trained
chemist who discovered so much
about ̒ SURFACE TENSION’
Phil chose Agnes Pockels

4.  Surfacetension defined as the tension of the surface film if a liquid caused by the particle attraction in the
surface layer by the bulk of the liquid which tend to minimize the surface area. It’s an important property that
marked influences the ecosystem. Surface tension, for example, is measured when critical micelle
concentration needs to be determined.
 Interfacialtension is defined as the force per unit length(l)parallel
to the interface to counter balance the net inward pull. Interfacial tension on the other hand is important
parameter in emulsion stability.

5. yes, several insects are able to walk in water such as water strider.
Their legs are formed to distribute their weight, causing the surafce of the liquid to
become depressed, minimizing the potential energy to create a balance of forces so that
the strider can move across the surface if the water without breaking through the
surface.
Yes, Neddle floating on water,Though the density of
these objects is greater than water. The surface tension
along the depression is enough to counteract the force
of gravity pulling down on the metal object.

6. 1. Natureoftheliquid
2. temperature:- Surface tension decreases with increasing of temperature .,i,e. with an
increase ofkinetic energy of the molecules.
γ = γ0 (1-T/Tc)1.2
3. soluteconcentration:- The quantitative relation between solute distribution and surface
tension is expressed by Gibbs adsorption isotherm- г = -c/RT. dγ/dc.
4. IntermolucularForces:-Surface tension is dependent on the strength of intermolecular
forces,. If there are weak intermolecular forces then there will be lower surface
tension and if there are strong intermolecular forces there will be larger surface
tension.

8. Surface tension at any point of circumference of
capillary tube = γ cos θ
Total upward force = 2πr γ cos θ
Counter balancing force due to weight of the column
= m g
= πr2h (ρ – ρ0) g + w
At equilibrium
2πr γ cos θ = πr2h ρg [ρ >> ρ0}
γ =rhρg/2cos θ
In case of water θ is taken as 0. ie, cosθ = 1
Thus
γ = 𝟏/𝟐 rhρg
Capillary Rise Method

9. When radius of narrow capillary is less than 0.01cm (r1) and wider is
greater than 0.2cm (r2) surface tension is given by
𝛾 = 𝐴𝑃[1 + 0.67𝑟2𝑔 𝐷/𝑃 ]
Maximum Bubble Pressure Method

10. Drop Method
Find average weight of drops
γ = w/2 π r
Generally relative surface tension with respect to water is
found out
γ l / γ w=w l / w w
Dropweightmethod
Dropcountmethod
Count the number of drops formed till the liquid reach mark B
γ = w/2 π r n
Generally relative surface tension with respect to water is found out
γ l/γ w= d l n w /d w n l

11. • The force measured in torsion balance will be equal to the
surface tension around the perimeter of the plate
W = 2 (L+T) γ
γ =W/2 (L+T)
Wilhelmy Plate method

12. • Force require to detach the ring from the surface
is obtained from the scale
• The force is proportional to surface tension
Ring Detachment Method
P = 2π(r1+r2) γ
γ = P / 2π(r1+r2)
r1 and r2 are inner and outer radius of the ring
For thin rings r1 = r2 = r
γ = P / 4πr

13. According to Archimedes law, the neddle or insect must be submerged
in the water, but due to surface tension it’s floating on water, which
means that it break the Archimedes principle that’s like in many
cases surface tension breaks many scientist’s principle. And by the
5 method we can determine surface tension that mainly acts to
reduce the surface area of a liquid depends on the composition of
the vapour phase.