HELP Calculating contact angle of benzene.

In summary, in an experiment to determine the contact angle for benzene on glass, benzene rises to 1.71 mm in a certain capillary tube at 20.0 C while water rises 4.90 mm at the same temperature. Given the densities and surface tensions of benzene and water, the contact angle for benzene can be calculated using the equation y1 = cosθ + y1,2 - y2 = 0, where y1 is the surface tension of benzene, y1,2 is the surface tension of benzene on glass, and y2 is the surface tension of water. The surface tensions of water can be assumed to be theta = 0.
  • #1
Saterial
54
0

Homework Statement



In an experiment to determine how well benzene wets glass, benzene was found to rise to 1.71 mm in a certain capillary tube at 20.0 C. In the same tube, water rose 4.90 mm at 20.0 C. Calculate the contact angle for benzene, give that at 20.0 C, benzene = 0.879 gcm^-3, pwater = 0.998 gcm^-3, benzene = 2.89 * 10^-2 Nm^-1 and ywater = 7.28 * 10^-2 Nm^-1. The contact angle for water is assumed to be theta = 0.

Homework Equations


y1 = cosθ + y1,2 - y2 = 0


The Attempt at a Solution



I don't know where to start. I know y1 can be found by finding the capillary radius of water and using that for benzene. But how do you find y1,2 and y2? Aren't they surface tensions of the solid glass surface which is not given?
 
Physics news on Phys.org
  • #2
At first glance, and without working it on paper - can't you calculate them from the information about water?
 

Related to HELP Calculating contact angle of benzene.

1. How is the contact angle of benzene calculated?

The contact angle of benzene is typically calculated using the Young-Laplace equation, which takes into account the interfacial tension between benzene and the solid surface, the density of benzene, and the gravitational constant. This equation can be solved using various techniques, such as the sessile drop method or the captive bubble method.

2. What factors affect the contact angle of benzene?

The contact angle of benzene can be influenced by several factors, such as surface roughness, surface energy of the solid, temperature, and the presence of impurities on the surface. Additionally, the type of solid surface and the concentration of benzene can also affect the contact angle.

3. Why is the contact angle of benzene important?

The contact angle of benzene is an important physical property that can provide valuable information about the wettability of solid surfaces. It can also be used to characterize the surface energy of materials and the interactions between a liquid and a solid surface. This information is crucial in various industries, including coatings, adhesives, and pharmaceuticals.

4. Can the contact angle of benzene be measured accurately?

The contact angle of benzene can be measured with high accuracy using modern techniques and equipment. However, it is important to ensure that proper experimental conditions are maintained, such as controlling the temperature and avoiding contamination of the surface. Additionally, multiple measurements should be taken to obtain an average value and reduce error.

5. How is the contact angle of benzene used in research?

The contact angle of benzene is a widely studied topic in research, particularly in the fields of surface science, materials science, and colloid and interface science. It is used to investigate the surface properties of materials, study the effects of surface treatments and coatings, and understand the behavior of liquids on solid surfaces. It is also used in various applications, such as anti-fog coatings and microfluidic devices.

Similar threads

A Confusion of the scale of contact line dynamics and capillary flow
    • Mechanics
Replies
1
Views
1K
Calculate Capillary Depression of Mercury in Glass Tube
    • Introductory Physics Homework Help
Replies
4
Views
5K
Calc III, Vector trouble, help would be great
    • Introductory Physics Homework Help
Replies
3
Views
7K

Hot Threads

Recent Insights

Back
Top