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.
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.
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.