Tuesday, December 12, 2017

100 Days of Science- #12 Why You Can Snuff Out a Candle with Baking Soda and Vinegar.

My boys and I were intrigued when we read that the reaction between baking soda and vinegar can be used to put out a candle. 

They love any science project working with baking soda and vinegar so we just had to try the experiment for ourselves! 

We took out:
 a small bowl with a flat bottom
baking soda
tablespoon measure
2 tealight candles

First we measured 3 tablespoons of baking soda into our bowl and tapped the bowl on the table to make sure it was evenly distributed.

Next we added our two tealights and light them using our lighter.

We let our candles burn for a minute or two to make sure the flame had really taken. 

Then we slowly poured 2 Tablespoons of vinegar into the bowl; making sure NOT to drop the vinegar onto the candles or flames but making sure to have it land in the baking soda.  Almost immediately the chemical reaction between the baking soda and the vinegar put out the flame.

We assumed that the bubbles popping around the candles blew out the flame with the air that was inside the bubbles so we decided to try and re-create the experiment with a taller candle... this candle was equal in height to our bowl.

We hypothesized that this might not work with a larger candle.  The boys thought we might need to increase how much baking soda and vinegar we used. 

We decided to start out just using the  3 Tablespoons of baking soda like our original experiment.

We added our 2 Tablespoons of vinegar and while it took a moment or two longer the candle flame flickered and died right out.

So we turned to our book to figure out HOW this worked! 

Candles need oxygen to burn; which we knew. 

When we added the vinegar to the baking soda the reaction of the two chemicals created carbon dioxide bubbles and since carbon dioxide is heavier/ denser than oxygen it sinks down into our bowl below the oxygen.  As the carbon dioxide sinks it pushes the oxygen out and the candle is snuffed out.

We then talked about the different types of fire and the different types of materials used to put them out. 

It was such a fun and informative science lesson!

Others in this series:

2.  Field Trip to the Ecotarium 
3.  Learning About Air Molecules

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