What is the capilary rise of ethanol in a glass tube with a 0.1 mm radius if the surface tension of ethanol is 0.032Jm2 and the density of ethanol is 0.71gcm3

Question

What is the capilary rise of ethanol in a glass tube with a 0.1 mm radius if the surface tension of ethanol is 0.032J/m2 and the density of ethanol is 0.71g/cm3

Answer 1

We can use the equation h = 2Tcosθ/rpg

h = height of ethanol inside the tube relative to that outside the tube

T = surface tension = 0.032J/m2 = 32 mN/m = 0.032 kg/s² (1N = 1kgm/s²)

θ = contact angle which is assumed to be zero if it is assumed the ethanol spreads out evenly

r = radius of the tube = 0.1 mm = 0.0001 m (1m = 1000 mm)

p = density = 0.71g/cm³ = 710kg/m³

g = gravity = 9.8 m/s²

h = (2)(0.032)/(0.0001)(710)(9.8) = 0.009 m = 9 cm