New Experiment 1: Purple Cabbage

Pictures of the new experiment taken at every half-hour interval. Shown below.

Time: 30min 

(Sorry, this picture was taken with the wrong tag.

Should be: pH 7 purple cabbage.)

Time: 60min

 

Time: 90min

Time: 120min

  


Time: 150min

 

Time: 180min

New Experiment Preparation

On 17th July, I carried out the new experiment:

White vinegar, distilled water and baking soda

Testing of pH for the different liquids

Vegetables at 0 min (before soaking)

Set-ups overview 
(as you can see from the picture, the purple cabbage slices immersed in pH 4 and 9 are already showing some reactions!)

Back to School (After June Holidays)

I had my elevator pitch and my talk with Ms Tan some time ago, and now there are many things for me to do. 

1. I need to quantify my results. How to do this? Either use a colour chart, or use the colour picker option in Photoshop. However, using a colour chart might present some difficulty as the chart does not have a unit of measurement. Instead, there are only string of letters and numbers that do not make a lot of sense. Photoshop would seem to be a more ideal choice here, but there are three values Hue, Saturation and Brightness so I have to choose the most appropriate one as my independent variable.  
2. Under the suggestion of Ms Tan, I will repeat my experiment, though slight changes will have to be made. Since I do not have the range of pH anymore, I will have to make do with household products such as vinegar and baking soda. Also, while the duration of the experiment will be kept the same (3 hours), I will take pictures of the set-ups at every half-hour interval. This way, I can make use of this new set of information by plotting a graph which shows the relationship between the hue of the pigment over time while being soaked in a particular pH.
3. After collecting the data and during the analysis of my results, I could categorise my data in the following manner (as suggested by Ms Tan) to make more meaning out of the information:

1. Leaves

• Purple cabbage
• Spinach

1. Roots

• Radish
• Carrot

1. Fruits

• Green pepper (which can then be compared to spinach as they both have chlorophyll)

Since there isn't a lot of time left, I have decided to conduct the new experiment on only purple cabbage and spinach, since purple cabbage displayed the most obvious results previously and both vegetables are leaves. Updating soon!

Apologies and Others

Really sorry but all the entries regarding the experiments in Inner Mongolia should have been up much much sooner, but the blogger was blocked in China! So all the above posted stuff is what I have been hoarding over the past month! More updates on this project to come soon...




Also, here are some websites that I have been perusing:
http://chemistry.about.com/od/acidsbase1/a/red-cabbage-ph-indicator.htm
http://www.funsci.com/fun3_en/acids/acids.htm
http://biofood.tripod.com/
http://www.ehow.com/info_8660001_science-experiments-purple-cabbage.html


They are mainly about purple cabbage as a natural pH indicator, which explains the colours in the liquid for my earlier experiments for purple cabbage (and radish, since they both contain anthocyanin).

Experiment 5: Radish

Radish is my last test subject! The strips in the acid range faded into a pinkish-orange colour, while those in alkaline turned purple-bluish at the sides. The liquid in pH 2 became orange, pinkish in pH 3 and light green in pH 12. Both radish and purple cabbage contain anthocyanin, it seems that radish, like purple cabbage, can be used as a pH indicator. 

Experiment 4: Spinach

I experimented on spinach next. It is leafier than the green pepper, so I was hoping that it would show more results. As can be seen below, the final results are largely similar to that of the green pepper.