shayan825 said:when we try to measure surface tension of different concentrated solutions of n-butanol with a tensiometer, we have to go from lower to higher concentration and not the other way around. what is the reason for that?
epenguin said:Firstly what does 'go from' mean? Describe an experimental procedure in such a fashion we will know what it means.
Then try and make a hypothesis yourself.
shayan825 said:We have n-butanol solutions ranging from 0.1 to 0.8 M, which we are supposed to measure their surface tensions. We have to start from the most dilute solution and go up in concentration until we reach 0.8 M. We cannot start from the most concentrated one and go to the most dilute one or just randomly pick a solution and measure the surface tension.
epenguin said:If you were asked to measure surface tensions and your posts were the description of how to do it, would you have any clue what to do?
If you can describe exactly what you do maybe someone can help (unfortunately I have to go now).
epenguin said:Well I have to guess these were not experiments starting each time completely afresh, the result of a measurement should always be the same. I guess you used the same wire and changed butanol concentrations adding butanol "going up" and diluting it "going down". It has the sound of failure to attain equilibrium. Perhaps as you dilute it is difficult for the butanol that has attached to the wire to dissociate, some always sticks there and equilibrium is not attained. Perhaps even if you dip it in water between measurements. I don't know anything about this but that is an obvious possibility.
How you clean what I read is such a delicate thing I have no idea.
shayan825 said:we did it using du nouy ring method. we calibrated the instrument with water and then measured the surface tension of each solution in an increasing order. the solutions were prepared from before.
epenguin said:Did you measure with water in between butanol measurements?
Surface tension is a physical property of liquids that describes the cohesive forces between molecules at the surface of the liquid. It is the reason why liquids tend to form droplets and maintain their shape on a surface.
The surface tension of a liquid is directly proportional to its concentration. This means that as the concentration of a liquid increases, its surface tension also increases. This is because more concentrated liquids have stronger molecular interactions, resulting in a higher surface tension.
Yes, surface tension can be measured using a variety of techniques such as the drop weight method or the capillary rise method. These methods involve measuring the force required to break the surface tension of a liquid or the height to which a liquid can rise in a capillary tube, respectively.
Surface tension plays a crucial role in determining whether an object will float or sink in a liquid. If the surface tension of the liquid is greater than the weight of the object, the object will float. If the surface tension is less than the weight of the object, it will sink.
Yes, surface tension can be changed by altering the concentration of the liquid, temperature, or by adding substances such as surfactants. Surfactants are molecules that can lower the surface tension of a liquid by disrupting the cohesive forces between the molecules at the surface.