My aim it to find out the different types of liquids are more or less viscous than each other and why. Some liquids flow more easily than others do. For example, honey is very “thick” and flows very slowly. Water is thin and flows very quickly. So honey is more viscous than water. Liquids that are made up of small molecules have a low viscosity and liquids with long chain molecules (such as plastics) have a much higher viscosity. The viscosity of materials generally decreases with increasing temperature. (EXAMPLE) A definition of viscosity; “Viscosity is a measure of a fluid's resistance to flow. It describes the internal friction of a moving fluid. A fluid with large viscosity resists motion because its molecular makeup gives it a lot of internal friction. A fluid with low viscosity flows easily because its molecular makeup results in very little friction when it is in motion. Gases also have viscosity, although it is a little harder to notice it in ordinary circumstances.” (1) As temperature increases, the average speed of the molecules in a liquid increases and the amount of time they spend "in contact" with their nearest neighbours decreases. Thus, as temperature increases, the average intermolecular forces decrease. The exact manner in which the two quantities vary is nonlinear and changes abruptly when the liquid changes phase. (2)
I am going to use the following alcohols:
As there are many of them I am not going to use all of them, only a couple, because it would take time doing all of them, also we don’t have a lot of time in our lesson.
My aim is to find out why some liquids flow more freely than others I am also going to investigate the different alcohols. Hypothesis:
I predict that the more carbon molecules it has the less viscous it is. So it would take longer to flow. It is because of the types of alcohol. For instance Propanol is less viscous than Octanol. Preliminary experiment:
I carried out a preliminary experiment with different alcohol for each experiment. We did this experiment only once just to get an idea of which experiment seemed the best for us to do. The results are shown in the table way below. Aim:
The aim of this was to find out which experiment we wanted to do and which seemed the best to us also which one was fairer and would be easier for us to do and explain why we chose the experiment we did. Prediction:
Once I saw our teacher show us the experiment I thought the Tilt Test would actually be ‘cool’ to do but I didn’t want to make my mind up just yet so I tried all of them out. I predict that once you go down to the alcohols with the more carbon lengths are more viscous.
* Ethanol (2),
* Propanol (3),
* Butanol (4),
* Pentanol (5),
* Hexanol (6),
* Heptanol (7),
* Octanol (8),
* Dectanol (10))
For Tilt Test:
* White tile
* Clamp Stand
* China graph Pencil
For Glass Tubing:
* Clamp Stand
* Blue Tack
* Air Bubble
* Clamp Stand
For Ball Bearing:
* Test Tube
* Test Tube Rack
1. Hold the bung with your thumb and turn it.
2. Quickly time the time taken for the ball to move up.
3. Write down the time taken.
1. Mark the tile from the top horizontally same for the bottom. 2. Get the alcohol and put a drop at the top before the black line so you can measure it easily. 3. Time the time taken for the liquid to flow down at your finish line. 4. Then write down the time taken.
5. Wipe off the liquid and start again from No.2.
1. Turn the tube upright by holding the clamp not the tube. 2. Time the time taken for the bubble to...