DAY 1-Colourful Chemistry
Cabbage Indicator
We did a experiment on cabbage indicator to found out the special properties of the common cabbage we have at home everyday.We boiled it in a beaker with deionised water and filtered out the cabbage,after that,we poured the water(that smells like cabbage...wait,isn't it suppose to be like that??) into four beakers,containing 2cm3 of vinegar,sulfuric acid,ammonia and sodium hydroxide separately.And POOF!!Vinegar(which is ethanal acid) turned pink,sulfuric acid turned red and ammonia turned green while sodium hydroxide...forming a line of colours(too bad i didn't take a photo).Question:Why?(duh)Cabbages have the property of indicating the ph level of a substance,as sulfuric acid ,the lowest ph level,is 1ph,it turned red,follwed by vinegar which is 2ph,turning pink and ammonia turning green as it is 10ph while the highest ph level,sodium hydroxide turned yellow.Lowest ph means most acidic(sour) while highest ph means most alkaline(sweet)
O.o....purpleA spectacular reversible reaction by the trainer(cause there is some dangerous reaction,fumes:O)
Blue solution(sulfate) turns green when hydrochloric acid is added(reacts and copper is displaced,less reactive,as hydrochloric acid is green,the solution turns green)Finally,the solution starts fuming when ammonia is added(ionised ammonia escaped as gas)....tada!!this is spectacular....rite??Colour constantly change as it is constantly being replaced.
Valentine solution
10 drops of phenolphthalein + 100 ml of deionised water +3 drops of ammonia in 1 beaker,heat it until it loses colour and take it off and let it cool.Loses colour as when heated,the back ward reaction(NH3+N2)<->NH4+OH) speeds more so less ammonium(ammonia is a weak alkaline,so it ionises back to normal) and hrydroxide ions are present,therefore,sloution becomes neutral and is colourless.It could work with other acids and alkaline as long as it is less reactive like gold.
Day 3-Biology(vitamins and enzymes)
Staying young with vitamin E
First,we lay out three petri dishes and label them with air,oil and vitamin e separately.W then take three slices of apple and coat two slices with oil and vitamin E according to the label and leave one slice exposed directly to air as control.
Colour changes in a decreasing manner of Apple exposed to air,apple coated with mineral oil and then,apple coated with vitamin E.
This tells us that Vitamin E prevents the cells from being exposed to air,thus is an antioxidant to help us keep young.
Pictures-
Physics-we did sound symphony,two-hoop plane,flying balloon,rainbow paper,surface tension and coupled pendulum
These 5 days have really been fun and meaningful as i have learnt a lot of things that are out of the Textbook.Whether is it chemistry,physics or biology,i would really like thank all the sec4 trainer who had been patient and given their best to let us have fun.In chemistry,i learnt about the different reactions that would take place in different equations(like deionised ammonia in sulfate),in biology,i learnt about the different properties of vitamins and enzymes that viatmin c causes redox(reduction+ oxygenation) which gains electron and and finally,in physics,i learnt about the refraction index,frequency and laws of Newton's finding like the law of inertia.I would opt for science eureka again next year as it is fun!!!
