Tuesday, June 7, 2011


The focus of this project is to extract caffeine from black tea, for example the bags of milk tea we brew. With Calcium Carbonate added with 10 bags of black tea and 500ml of hot water, we would brew the tea, and extract caffeine with the help of separation methods using the help of funnels. We were first supposed to filter out the residue using the Buchner Filter. Then, we would use the separating funnel. We also used the Rotary Evaporator, which made the last caffeine become powder-like. Afterwards , we had a demonstration of the effect of dry ice and liquid nitrogen. The professor firstly place the universal indicator solution in plain water. The colour of the water changed to green in colour. Afterwards, she place some alkaline water in the water, and the water turned purple. She added a few pieces of dry ice in the water, and the water changed colour to getting more and more acidic. The changing of colour stopped when the acidity of the water is around pH 5.

She also demonstrated using liquid nitrogen. She placed the gloves in the liquid nitrogen, and took it out, stepped on it, and the whole glove crumpled and crush. A few seconds later, the glove went back to the original shape. Afterwards, she took a frying pan and cracked open a raw egg, poured some liquid nitrogen in. A few seconds later, a frozen raw egg was seen, with the whole frying pan freezing. The pan went back to its original temperature after 10 minutes, and the raw egg still have not returned to its original shape at the end. The professor also tried to make ice cream with Coffee, milo and liquid nitrogen, along with a little bit of dry ice. She mixed the coffee, milo and liquid nitrogen, with a helper, and stirring the mixture at the same time. To make a fizzy effect like soft drinks, she also added a little dry ice into the mixtures. Afterwards, we see a coffee milo ice cream with fizzy effect made.

She also placed a half blown balloon on top of the beaker filled with liquid nitrogen, the air in the balloon contracted after a while, as the temperature of the liquid nitrogen is too low (-196degree celcius).

Rubber materials like the tubes when place into the liquid nitrogen, it can be broken by a hammer.

Sunday, June 5, 2011

Our Gains.

As a group, discuss how the project has helped to deepen your understanding/ broaden your awareness on selected subject discipline(s)

In the lab, we have to notice and keep in mind the lab safety rules, and we must be careful in the lab, to dispose the solvents in the right bin, and also not to touch dangerous things. Dry ice condenses when it is released to the surrounding air in room temperature, as dry ice itself is very cold. Liquid nitrogen evaporates

describe how the new learning is/ can be connected to what you learnt/ are going to learn

The learning made us be more cautious when we go back to school in the labs. We will also know that in the future, with harder experiments, we have to dispose our solvents properly in the right bin. We also gained knowledge on stuff hard to get, for example liquid nitrogen, and dry ice, about what happens when we pour them/ dip something into the liquid nitrogen, or place dry ice into water, or place it on the table. From both of this, we also learnt that when something colder touches something with a higher temperature, the item with the colder temperature will take energy from the material with higher temperature.

When appropriate, include photos and video clips to illustrate/ support your explanation

Our Accomplishments.

What is our end products/findings?
Our end product is the caffeine extracted. We also found out new knowledge like why is calcium carbonate used when we are brewing the tea. We also know why is magnesium sulphate is used along with the filter after we used the separating funnel.We also know why DcM is at the bottom of water.

A description/ explanation of your product/ findings
Calcium carbonate is used so as to solubilize the tea. We also know why is calcium carbonate used along with the filter after we used the separating funnel, as the magnesium sulphate absorbs water. DcM is at the bottom of water, as it is denser as it has chlorine in the solution.

Our Mission

What does the group need to accomplish at the end of the project?
Extracting Caffeine from beverages.