Tuesday, 12 July 2011
What child doesn't like a bit of magic and chemistry often provides a bit of magic. We added some white wine vinegar to a clear bowl (easy to see what was happening), then added a squirt of washing up liquid and some food colouring. We stirred it up and then added a teaspoon of bicarbonate of soda and watched.
The girls loved the foaming and then couldn't resist stirring it up, mixing and feeling it. They also enjoyed experimenting by adding more ingredients. It was quite interesting to watch them work out what was happening - both I and G knew it was something to do with the bicarbonate of soda and the vinegar. Miss I worked out something was going on to cause bubbles to be made and this must be due to gas being produced.
For those of you who like your facts ..this happens because the
bicarbonate of soda and vinegar react to produce water and carbon dioxide.
NaHCO3(s) + CH3COOH(l) --> CO2(g) + H2O(l) + Na+(aq) + CH3COO-(aq)
Acetic acid (the acid in vinegar) reacts with and neutralizes sodium bicarbonate (the bicarbonate of soda ). The carbon dioxide that is given off is a gas and is responsible for the fizzing and bubbling during the 'eruption'.
This was great for developing investigative skills (such as thinking about what might happen and trying to explain what had happening by using previous experience).