Firstly, we just have to comment that the enrichment programme lecturer did a great commendable marvellous wonderful excellent superbly splendid job in educating us with various different unfamiliar chemistry experiments,venturing with us into a new ground of chemistry.
Lets start the ball rolling with the first experiment.
1.Invisible Ink
This experiment takes place by reacting:
Potassium thiocyanate[KSCN] and Ferric chloride[FeCl3]
Equation:
KSCN(aq) + FeCl3(aq) -> [Fe (SCN)]^2+(aq)
colourless Brick red light red
When the lecturer added Ferric Chloride onto the piece of paper she had earlier prepared,
FeCl3 reacts with the KSCN to form Fe[(SCN)]^+2 solution which is visible to us.
and the WELCOME word slowly surfaced
Everyone was like.."WOAHHH"
and of course.."Awwwwwww.."
This is somehow similar to how Magic Pens work.You know those type you use when you are young,and you go" MUMMY..see..i know magic.i colour white on blue and i get yellow".It's all about chemistry reactions.So pleaseee..come back to Earth
See how the colour change in this video!
2.Think Ink
This is an experiment which react 2 colour reactants together
and after a couple of seconds, it turns dark blue
Searching more of the Internet, it shows how this works.
First, the iodate reacts with the bisulfite:
1) KIO3(aq) + 3 NaHSO3(aq) ---> KI(aq) + 3 NaHSO4(aq)
It can be written as
IO3-(aq) + 3 HSO3(aq)----> I-(aq) + 3 SO42-(aq) + 3 H+(aq)
Some formed iodide reacts with more iodate to get iodine (I2)
2) 5 I-(aq) + IO3- (aq)+ 6 H+(aq) ---> 3 I2(aq) + 3 H2O(l)
However, iodine will not react with starch as long as bisulfite is present. The reaction with starch is slower than the reaction with bisulfite. So the iodine will react with bisulfite to form more sulfate, until there is no more bisulfite.
3) I2(aq) + HSO3-(aq) + H2O(l) ---> 2 I-(aq) + SO42-(aq) + 3 H+(aq)
when there is no more bisulfite, I2 produced in (2) will then complex with the starch.
4) I2(aq) + starch(aq) ---> iodine-starch complex (blue-black)
CHIM uh..
Basically, when we were at the lecture hall, we were stunned by the result cause i think practically no one(except for teachers maybe) expected that.This experiment is cool man.
Noo doubt.
This's how the experiment goes..WATCH THIS(till 0:30)=D
3.Light Stick
Ah ha!This is my favourite..I never knew how light stick works until now-_-
So there..
The glow is the result of 2 chemicals mixing together.
1.Hydrogen Peroxide(H2O2)
2.Phenyl Oxalate Ester and Fluorescent Dye solution(C14H10O4.)
When we bend the light stick, we break the glass vial in the casing that contain the Hydrogen Peroxide solution.The H2O2 is released into the plastic casing where it reacts with the Phenyl Oxalate Ester and Fluorescent Dye solution.Then TADA..glowing stick.
Equation: cyalume + H2O2 + dye → trichlorophenol + 2CO2 + dye[♦]
watch this glow stick experiment!
4.Blue Bottle Experiment
This is the experiment of the blue solution.A bottle half-full of a colorless liquid is shaken and turns blue. On standing undisturbed, the blue color fades. The cycle may be repeated several times. Other colors can be produced by substituting other indicators for the methylene blue commonly used.
HA!WHY!?
Firstly,
Glucose (alkaline) + Methylene Blue(blue)--> Methylene White(colourless) [When shaked]
Methylene White -> Methylene Blue + O2 [when left untouched for couple of seconds]
It happens when shakened,Methylene Blue reacts with O2 in the flaska and get oxidised to become Methylene White.
When left undisturbed, Methylene Blue reduce to give back Methylene White(colourless) and O2
Here's a video
5.Cloth burning
If i were 6 instead of 16, i might be more surprised.
How can you burn a cloth without getting ashes as remains?
Science again.
Firstly, the cloth is soaked with 50% water and 50% alcohol.
It is soaked in the water first,then alcohol.
When the fire is ignited, the fire burns the alcohol instead of the cloth.
The water acts as a protection against the fire,which prevented the cloth from being turning into ashes.
Cant find any video on that.
But after researching on the Internet, people say this experiment is still dangerous as although the fire doesnt burn the cloth,it is still a real fire after all! duh right..
So must handle with care after all
6. Silver Mirror Reaction
Ionic Equation:
CH2OH(HOH)4CHO(aq) + 2(Ag(NH3)2)^+(aq) + 30H^-(aq) -> 2Ag(aq) + CH2OH(CHOH)4COO^-(aq) + 4NH3(g) + 2H2o(l)
Tollens’ reagent is a solution of silver nitrate, ammonia, and potassium hydroxide which produces a silver diamine complex [Ag(NH3)2]+. The solution is added with a sample of an aldehyde,mixed and shaken.The silver oxidises the aldehyde to a carboxylic acid which result in the silver to be reduced to elemental silver.This production of elemental silver slowly coats the flask with a thin layer of silver.
It was amazing when we see how the lecturer took the the big clear flask with the solution inside and turn it into a silver coated flask which is as reflective as a mirror.
I was stunned.Definitely.I didnt expect that.
bi ba pa ba bi ba pa ba bi pa ba pa pa bi ba..
7.Super Absorbent Polymer aka SAP aka(slush powder)
Absorb water to form Gel
Add salt to turn it back into liquid state.(reversible reaction)
SAP may absorb 500 times its weight (from 30-60 times its own volume), but when put into a 0.9% saline solution, the absorbency drops to maybe 50 times its weight.
Made up of:
-polymerization of acrylic acid blended with sodium hydroxide in the presence of an intiator to form a poly-acrylic acid
-sodium salt(sometimes referred to as cross-linked sodium polyacrylate)
used in
-candles
-diapers
-surgical pads and more..
video
Maybe this is a good idea for Bladder Buddy..
8.Genie in the Bottle
Equation: 2H2O2(aq)-----> 2H2O(g) + O2(g)
MnO2
(Manganese
Dioxide) as catalyst
When MnO2,a catalyst, is added into H2O2 in a bottle,a "mist" is seen.The "mist" we see is dense water vapour.
The reaction is EXOTHERMIC!the bottle gets a bit warmer after the reaction.
Bottle may shrink because of this reaction.(depend on what bottle used)
Genie In A Bottle Experiment - Funny home videos are a click away
9.Elephant Toothpaste
What is needed:
-30% Hydrogen Peroxide solution(stronger than average H2O2 and not available in stores)
-Detergent
-Manganese Dioxide(Catalyst)
-Colouring(optional)
How it works
Manganese Dioxide speed up the decomposition of Hydrogen Peroxide
2H2O2 --> 2H2O + O2(g)
Dishwashing detergent captures the oxygen that is released, making foam.
Add colouring to spice up the experiment.
Because of the fast decomposition, the foam formed in the tube expands so quickly and oozes out in large amount.Resembling Elephant toothpaste.
VIDEOOoo
10.Dragon Fire aka Fine Dust Explosion
Make use of Lycopodium powder, obtain from Lycopodium which is a genus of clubmosses, also known as ground pines.
-The powder is highly flammable.
-When blown toward a fire source, the fire emerged resemble fire blown out of the dragon mouth like the one you see in Shrek movie.
Lycopodium powder used in
-fireworks
-photographic flash powder
-fingerprint powders
Foooshhh
There you have it.This is our blog entry for this competition!
0911D owning chemistry..;D
Yawns..Time for bed-_-
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