How do you find the angle of contact in a capillary tube?

Given: Radius of capillary tube = r =0.5 mm = 0.5 × 10-3 m, Height of capillary rise = h = – 0.80 cm = – 0.80 × 10-2 m, Surface tension = T =0.465 N/m, Acceleration due to gravity = g = 9.8 m/s2, Density = ρ =13.6 × 103 kg/m³, To Find: Angle of contact = θ =? To Find: Density = ρ =?

How do you calculate contact angle?

Calculate the contact angle For example, if the gradient is 3, then you can use the relationship tan(θ) = (opposite/adjacent) = (3/1) to calculate the angle. Once you have the baseline and the droplet edge, you can calculate the angle between them.

What is angle of contact in capillary rise?

The contact angle is an angle that a liquid creates with a solid surface or capillary walls of a porous material when both materials come in contact together. A less traditional definition is the angle a liquid creates with the sides of a capillary when it rises in it to create a meniscus.

Which is the formula for capillary rise?

The rise of a column of liquid within a narrow capillary tube is also because of the surface tension. The formula for capillary rise (h) = 2T/rρg.

How do you find the angle of contact in surface tension?

If θ is 90°, then liquid meniscus will be plane. If θ is obtuse, i.e. θ>9o°, then liquid meniscus will be convex upwards. If angle of contact is acute angle, i.e. θ<9o°, then liquid will wet the solid surface….Surface Tension:

Surface Tension	Adhesive Force
Angle of Contact	Capillarity
Jurin’s Law

What is the angle of contact for a pair of solid and liquid?

The angle between tangents drawn at the point of contact to the liquid surface and solid surface inside the liquid is called the angle of contact for a pair of solid and liquid. It is denoted by θ.

What is angle of contact using the same explain capillary rise and fall?

If the adhesive forces between the liquid and the vessels wall is dominating then there will be a capillary rise. If the cohersive forces are dominating between the liquid and the vessel then there will be a capillary fall. If no forces are dominating then the angle of contact is equal to 90° itself.

Why do we measure contact angle?

Significance. The contact angle is important wherever the intensity of the phase contact between liquid and solid substances needs to be checked or assessed: coating, painting, cleaning, printing, hydrophobic or hydrophilic coating, bonding, dispersing etc.

What is Youngs equation?

Young’s equation is defined as: σsg = σsl + σlg ⋅ cosθ Where: σsg = the surface free energy of the solid. σsl = the interfacial tension between the liquid and the solid.

How is capillary pressure calculated?

Capillary pressure is defined as Pc=Pnw−Pw and for water saturation decreasing, Pnw outside the pore throat is greater than Pw inside the pore throat, resulting in a positive pressure.

How do you calculate capillary action?

If you dip a paper towel in water, you will see it “magically” climb up the towel, appearing to ignore gravity. You are seeing capillary action in action, and “climbing up” is about right – the water molecules climb up the towel and drag other water molecules along.

What is capillary rise Class 11?

Capillarity rise is due to the tendency of liquids to rise in tubes of small diameter in opposition to the gravity. For concave meniscus, the contact angle will be acute and for convex meniscus of liquid, the contact angle will be obtuse.