Practice Coursework Essay

Submitted By Wewgcsebiologu
Words: 1050
Pages: 5

Data Analysis
Hypothesis
“Liquids containing longer or larger molecules are more viscous”
Molecules
Name
Formula
Structure
Ethanol
C2H6O

Methanol
CH4O

Propanol
C3H8O

Butanol
C4H10O

Pentanol
C5H12O

Hexanol
C6H14O

Heptanol
C7H16O

Octanol
C8H18O

Possible Methods to Measure Viscosity
There are good and bad things about each of the experiments we could do to collect our data, the first method is the ball method in which we would drop a ball bearing into a large measuring cylinders of each liquid and time how long it takes to fall down.

The second method is the funnel method in which we would drop each liquid through a funnel and time how long it takes to fully flow through. One problem with this method is you would have to use a different funnel each time as residue may be left over from the previous liquid.

The final method is putting a sloped tile at a slant and using a pipette drop each liquid down the tile and time how long it takes between two points. One problem with this experiment is that you may hold it at a different angle each time you do it; you would have to have a regulation to angle to go from to make it completely fair.

I have decided to use the tile method for my work as it seems the easiest to do and doesn’t leave much mess behind; it is also easier to time.
Preliminary Work
We needed to test a few things before we could actually carry out the experiment, such as how much liquid we would drop down, the angle of the tile, how we would time the drip, the distance it would be travelling and how we would hold it up at an angle.

So to do our experiment we decided that we were going to drop one drop of the various alcohols down the tile and the angle of the tile was thirty degrees. We would time the drip with a stopwatch and as it went between two points drawn on the tile with a china graph pencil. We would hold it up at the angle of thirty degrees constantly by sticking it onto a gas tap with plastacine.
Safety
We would do a risk assessment because it is required by the school to do one, and the information we would get from it is that if there is a problem, what to do and how to prevent it from happening and hurting somebody.
Variables
Independent variable = the length of the liquid (amount of carbon atoms in it)
Dependant variable = the time it takes to flow down a tile between two points
Controlled variable = the amount of liquid, the way you drop the liquid, the tile, angle of tile, stopwatch, ruler

Equipment
Tile
Protractor
China graph pencil
Pipette
Gloves
Ruler
Stop watch
Alcohols
Paper towels

Method and Rationale
Method – Step by step
Why?
Firstly I will position the tile at thirty degrees and fixate it with plastacine
I will do this because that mean the experiment can be controlled
Then I will draw the lines on the tile to indicate the start and finish points
I will do this so I can see when the alcohols have started and finished and time it correctly
Then I will gather my various alcohols and get a clean pipette to get them out of the bottle
I will do this so I can perform the experiment
Then I will drop the alcohols down the tile and time them with my stopwatch
Also so I can perform the experiment and get my times
Results Table
Alcohol
Number of Carbon Atoms
Measurement 1
Measurement 2
Measurement 3
Mean
Range
Methanol
1
2.58
0.69
1.46
1.58
1.89
Ethanol
2
1.64
2.56
1.5
1.90
1.06
Propanol
3
1.75
1.31
2.34
1.80
1.03
Butanol
4
1.42
3.85
4.33
3.20
2.91
Pentanol
5
5.79
5.71
3.91
5.14
1.88
Hexanol
6
6.17
8.37
5.54
6.69
2.83
Heptanol
7
9.14
14.84
12.07
12.02
5.70
Octanol
8
9.81
15.21
13.41
12.81
5.40
Graph (on a separate page)

Data Analysis
My Data has a trend towards proving that alcohols with more carbon atoms…