Here’s some festive fun with a couple of red balloons, some cotton wool and two boiling tubes.
Santa’s challenge is to find out which special reindeer food makes Rudolph’s nose grow big the fastest.
Rudolph ready to blow!
1. Place 20ml 2M hydrochloric acid in a boiling tube and add Universal Indicator solution to give a deep red colour.
2. Push a small amount of cotton wool into the boiling tube so that it forms a platform above the acid. (Don’t use too much cotton wool, the least amount possible the better).
3. Add 0.5g sodium hydrogencarbonate to the tube so that it rests on the cotton wool.
4. Place a red balloon over the end of the tube.
5. Repeat steps 1 to 4 using 0.5g calcium carbonate instead of the sodium hydrogencarbonate.
When ready tilt the tubes so that the acid soaks through the cotton wool and comes in contact with the carbonates. Start a stopwatch and see which tube inflates Rudolph’s red nose the quickest.
Which food made the biggest nose fastest?
What is the name of the gas which inflates the balloon?
Can you write symbol equations for the two chemical reactions?
Can you show by calculation how much gas should be produced by 0.5g of each carbonate?
All other things being equal, which carbonate should produce most gas and inflate the balloon quickest?
Here are some cut out antlers which can be used to decorate the boiling tubes.
Cut out antlers
For the Belousov–Zhabotinsky reaction in a Petri-dish (3rd December 2013 post)
I used the following recipe:
6 cm3 0.5M potassium bromate(V), KBrO3
0.6 cm3 6M sulfuric(VI) acid, H2SO4
1 cm3 0.5M potassium bromide, KBr
2.5 cm3 0.5M malonic acid
1 cm3 Ferroin indicator solution (Merck commercial solution for waste water analysis)
I read in another source the Ferroin should be about 0.025M.
One mixes the ingredients in a boiling tube or small beaker sequentially in the order listed above.
Videos for the preparation of this mixture can be found here:
Preparation of a Belousov–Zhabotinsky reaction for use in a Petri-dish Part 1
Preparation of a Belousov–Zhabotinsky reaction for use in a Petri-dish Part 2
For the Belousov–Zhabotinsky reaction in a beaker (8th December 2013 post)
I used the following recipe:
100 cm3 1M sulfuric(VI) acid, H2SO4
2.86g malonic acid
1.04g potassium bromate(V), KBrO3
0.11g cerium (IV) sulfate, Ce(SO4)2.4H2O
0.5 cm3 Ferroin indicator solution (Merck commercial solution for waste water analysis)
A video for the preparation of this mixture can be found here:
Preparation of a Belousov-Zapotinsky reaction in a beaker
I have another recipe for this reaction in a beaker which is slightly different and I am going to try it out. In the animated .gif of the beaker reaction posted on the 8th December there was no green colour visible during the transitions and I’m hoping this second recipe will show a green colour.
Here’s a B/Z reaction in a beaker:
The small.gif should load quickly, but you many have to download the larger .gif below in order for it to play.
How many colours can you see?
In this post and in the one before it we have been looking at Belousov–Zhabotinsky reactions. What are the ingredients used in these B/Z reactions?
B/Z is shorthand for a Belousov–Zhabotinsky reaction.
These produce interesting patterns when carried out in a Petri-dish.
We carried out some B/Z reactions in our Chemistry Club the other day.
Here are some .gif animations of our results.
What happens when a B/Z reaction is carried out in a beaker?