HELP Calculating contact angle of benzene.

AI Thread Summary
To calculate the contact angle of benzene on glass, the experiment shows that benzene rises 1.71 mm while water rises 4.90 mm in a capillary tube at 20.0 C. Given the densities and surface tensions of both liquids, the relevant equation involves the surface tension of benzene, water, and the contact angle. The challenge lies in determining the surface tension of the glass surface, which is not provided. It is suggested that the surface tensions might be inferred from the water data, but clarity on how to derive these values is needed. The discussion emphasizes the need for a clear starting point in the calculations.
Saterial
Messages
54
Reaction score
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
At first glance, and without working it on paper - can't you calculate them from the information about water?
 
Thread 'Confusion regarding a chemical kinetics problem'

Thread 'Confusion regarding a chemical kinetics problem'

TL;DR Summary: cannot find out error in solution proposed. [![question with rate laws][1]][1] Now the rate law for the reaction (i.e reaction rate) can be written as: $$ R= k[N_2O_5] $$ my main question is, WHAT is this reaction equal to? what I mean here is, whether $$k[N_2O_5]= -d[N_2O_5]/dt$$ or is it $$k[N_2O_5]= -1/2 \frac{d}{dt} [N_2O_5] $$ ? The latter seems to be more apt, as the reaction rate must be -1/2 (disappearance rate of N2O5), which adheres to the stoichiometry of the...
View full post »

Thread 'Prove that evolution is constant (Provide at least two arguments to support your position)'

I don't get how to argue it. i can prove: evolution is the ability to adapt, whether it's progression or regression from some point of view, so if evolution is not constant then animal generations couldn`t stay alive for a big amount of time because when climate is changing this generations die. but they dont. so evolution is constant. but its not an argument, right? how to fing arguments when i only prove it.. analytically, i guess it called that (this is indirectly related to biology, im...
View full post »

Similar threads

Calculate Capillary Depression of Mercury in Glass Tube
Replies
3
Views
6K
Calc III, Vector trouble, help would be great
Replies
3
Views
8K

Hot Threads

Recent Insights

Back
Top