Sodium bicarbonate Volcano

Purpose:

The volcano can give off colored lava and heat. You will need to wear goggles, chemical apron, and gloves.

Materials:

• casserole dish

  600 ml beaker

  50 ml concentrated HCl

  10-15 g NaHCO₃

  1 ml Bromocresol purple or other indicator

Procedure:

1. Place the beaker in the casserole dish.

   Add 200 ml of water to the beaker and stir in 10-15 g of NaHCO₃.

   Add the 1 ml Bromocresol purple or other indicator to the solution.

   Carefully add the 50 ml concentrated HCl to the solution.

   Disposal is down the drain with small amounts of waste being added to large amounts of water while you are wearing your safety equipment.

Discussion:

An orange volcano erupts from the beaker due to carbon dioxide being formed. The foam is a mixture of orange and purple due to the acid and bicarbonate (HCO₃). If you have had biology you can relate this to the carbonic acid-bicarbonate buffering system in the blood.

Hot Volcano:

Add a small amount of warm glycerin to potassium permanganate and you will see the oxidation of glycerine by the permanganate. This produces lots of smoke and fire, but is relatively safe. Check out the temperature of glycerine to see how quickly the reaction occurs (try glycerine that has been in a refrigerator).

Back to top