Particle Theroy of Matter - Convection

Aim - To observe convection in a liquid 

Equipment - 200 ml beaker, water, tweezers, a crystal of potassium permanganate, a drinking staw, bunsen burner, heat mat, tripod and gauze mat.

Method -  
1. set up a bunsen burner on a heat proof mat, Put the gauze at on the tripoad but leave it just to one side of the bunsen burner.
2. Fill a 200 ml beaker with 150 ml cold water.

3. place the beaker on top of the tripod and guaze and allow it ot settle for a few minutes.

4. carefull inster the drinking straw down one side of the beaker, ensuring the straw is toucing the bottom of the beaker. be careful as you do not want to disturb the water to much.

5. using tweezers, drop a crystal of potassium  permanganate down inside the straw. wait for the crustal to settle on the bottom of the beaker.

6. very gently, so you don't distirb 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, obseve.

Observation -  The crystal dissolved and made a thick purple cloud and dissolved more rappidly on the heated side of the beaker. the purple moved up the beakers side and then formed a big circle and made its way around the beaker.

explanation -  this is because of convection currents. Hot water wanting t omove to a cooler place