CONVECTION EXPERIMENT ⚛️

When particles are heated, the distance between the particles increases. This means that objects will expand. When liquids or gases expand they become less dense. A gas or liquid which is less dense will rise through a more dense gas or liquid. This is the explanation for the well-known tendency of hot fluids to rise and cold fluids to sink. Scientists call this process convection.

AIM: To observe convection in a liquid. 
EQUIPMENT: 200mL beaker, water, tweezers, a crystal of potassium permanganate, a drinking straw, Bunsen burner, heat mat, tripod, gauze mat, petri dish. 
METHOD: 
1. Set up a Bunsen burner on a heatproof mat. Put the gauze mat on the tripod but leave it just to one side of the Bunsen burner.
2. Fill up at 200mL beaker with 150mL cold water. 
3. Place the beaker on top of the tripod and gauze and allow it to settle for a few minutes.
4. Carefully insert a drinking straw down one side of the beaker, ensuring the straw is touching the bottom of the beaker. Be careful as you do not want to disturb the water too much.
5. Using tweezers, drop a crystal of potassium permanganate down the inside of the straw. Wait for the crystal to settle on the bottom of the beaker.
6. Very gently, so to not disturb the water, remove the straw.
7. Light the Bunsen and slide it under the tripod so that you are only heating the outside of the beaker where the crystal is. Observe. 

OBSERVATIONS:
As time progressed. the purple hue of the permanganate spread to colour the entire water contents. It started to get darker, especially around the bottom of the beaker, and there were some particles floating on the meniscus of the water. We noticed it smelt like burnt toast throughout the experiment.

In a petri dish, we filled it up with cold water and then dropped the permanganate in it. We noticed the beaker and dish both appeared different in hue due to the difference in temperature of the water. 
By doing this we were able to see how the crystal of potassium permanganate acted in both hot and cold water. 

EXPLANATION:
1. Decide whether the following statements are true or false.
(a) Convection occurs because the particles expand. True.
(b) Hot water rises because the hot particles are more spread out.
False. 
(c) An object that is very dense will float on a less dense object.
False.
(d) Cold water sinks below warmer water because it is more dense. 
True. 

I am wondering... what would happen if we stirred the solution or allowed it to boil.