An IB chemistry HL internal assessment.
Research question: Analysing the denaturation rate of egg white and corresponding activation energy with acetic acid, by experimenting with temperatures varying from 200 to 260 degrees Celsius, increased in 10-degree intervals
Independent variable: Temperature of the water
Dependent variable: Rate of denaturation of the egg white
Control variable: Type of egg, volume of egg, volume of water
Procedure:
Prepare acetic acid solution
Prepare egg white by separating the yolk content
Measure the absorbance of the egg white before heated up
Preheat the water baths to desired temperature (30-100 degrees)
In each test tube combine 10mL of egg white with 10mL of acetic acid solution
Place the test tube into the water bath
Record a timer until the egg starts to denature and stop the timer (egg starts to turn turn whiter in colour and more opaque)
Put the egg white in the spectrophotometer to measure the absorbance after the egg has denatured (600 nm and beyond is already denatured), make sure the clear side is facing outwards
make sure to calculate the activation energy using the data and show working and graphs
|
Temperature (degrees celsius) |
Time (s) |
|
200.00 |
2.51 |
|
210 |
2.40 |
|
220 |
2.34 |
|
230 |
2.26 |
|
240 |
2.22 |
|
250 |
2.18 |
|
260 |
2.12 |
|
270 |
2.04 |