Diving Ketchup (Creative Chemistry Experiments)

You will need:

1. 1-litre transparent plastic
   bottle.
2. Salt
3. A few ketchup packets
   from any fast food
   restaurant
4. Water

Understand the workings of density and buoyancy of an object through this easy but fun experiment.

INSTRUCTIONS

1. Firstly, you need to test whether your ketchup packet will float or sink.
2. Half fill a bottle with water, scrunch up the ketchup packet with your hand and carefully push it through the bottle without tearing it.
3. If it floats, you are set to perform the experiment.
4. If it sinks, however, then take another ketchup packet and perform the same test.
5. If it floats, leave the ketchup packet inside and fill the bottle all the way with water.
6. Put the cap of the bottle back on.
7. Once the ketchup packet has stayed floating, gently squeeze the bottle in the centre and release.

RESULT

Once the bottle is squeezed, the bubbles trapped inside the packet of ketchup become smaller and thus make the ketchup denser than the water, making it sink. When you stop applying pressure to the bottle, and release it, the bubbles trapped inside the ketchup packet once again expand making the packet buoyant!