We had lots of fun as Chemical, Electronic and Civil Engineers this week during Engineers’ Week 2023

We carried out the following experiments:

Mummy Apples 

This experiment  demonstrates the Chemical Engineering and Food Science process of Food Preservation.
Results :

Using salt and baking soda, we carved and dehydrated (dried out) an apple to create mummified fruit. Salt is a desiccant, which is another word for a chemical that’s good at pulling water out of other things. Not only does it speed drying, it kills any microbes that might cause the apple to spoil.

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Peel a Raw Egg

We experimented scientifically to observe the chemical reaction between Acids and Alkaline substances.
Results:

The shell of an egg (typically a chicken egg) is made up of primarily calcium carbonate. If you soak this egg shell in vinegar (which is about 4% acetic acid), you start a chemical reaction that dissolves the calcium carbonate shell. The acetic acid reacts with the calcium carbonate in the egg shell and releases carbon dioxide gas that you see as bubbles on the shell.

CaCO3 (s) + 2 HC2H3O2 (aq)   →   Ca(C2H3O2)2 (aq) + H2O (l) + CO2 (g)

The egg insides remain intact and are held together by the two fragile membranes just inside the shell.

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We explored Electronic Engineering:

We learnt that  Sound is a Mechanical  Wave. 

o The sound of the human voice is created by the vibration of our vocal cords when we speak. During this activity, the vibration of vocal cords causes the air inside the cup to vibrate. The vibrating air caused the cup to vibrate and eventually the vibration was conducted to the string connecting the two cups. Sound waves generated by one student are conducted to the second cup by the string to become a detectable sound. 

o In this activity, the cup, air, and the kite string were the media conducting the vibrations created by the vocal cords when speaking. When the string was stretched between the two cups, the  vibrations were easily conducted by the string from one cup to the other. However, when the string was slack or sagged between the  cups, the vibrations were less likely to reach the second cup.

o When the string was held by another student, the vibrations could no longer travel along the string from one cup to the other. The string ceased to vibrate at the point where it was held.

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We used our Civil Engineering skills  and constructed our own Lighthouse Electrical circuits. We thoroughly enjoyed Engineers Week and attach some pictures of our trainee Engineers in action.