University:
North Idaho College
Course:
PHYS-211 | Engineering Physics I
Academic year:

2023
Views:

126

Pages:

4
Author:

Hani T.

Effect of Temperature on Surface Tension Surface Tension decreases with increase in Temperature and vanishes at the critical Temperature. Increase in Temperature increases the energy of the Molecules and tends to reduce Intermolecular forces. Thus less work needs to be done to increase the Surface Area. Several attempts have been made to quantify the effect of Temperature On Surface Tension. Most are at Best empirical one Such attempt is due to Ramsay and Shields. γ [M/d]^(2/3) = K (Tc-T-6) where γ is the surface Tension, M is the Molecular weight, d is the Density, Tc is the Critical Temperature and T is the Temperature of the liquid. As K is proportionality Constant a plot of γ[M/d]^(2/3) versus T is a straight line with an intercept on the Y-axis as Y[M/d]^(2/3) = k Tc - 6k - kT The above empirical Relationship is applicable to simple liquids which do Not show molecular association. (due to hydrogen bonding) or dissociation Two other empirical Relationships are the Eotvos equation which is: Y = [M/d]^(2/3) = K (Tc - T) and the Macleod equation which is Y = C (D - d)^4 where D is the density of the liquid, d is the density of the vapour and C is a constant of proportionality