Calcium and Water Lab Activity

Purpose: To observe what happens when calcium metal comes in contact with water.

Materials:

Materials & Equipment · medium test tube · calcium metal · test-tube rack · tweezers/scoopula · water · large test tube (must · candle fit over medium test tube) · matches or flame striker · Phenolphthalein (indicates a base) · wooden splints

Procedure: Sketch a labelled diagram of the lab set-up in the box below.

1. Place the medium test tube in the test-tube rack, and then fill it with water to a depth of about 3 cm. 2. Light the candle. Light a wooden splint, and bring it near the mouth of the large test tube. Observe. Put the splint out. Record your observations. 3. Place three drops of phenolphthalein into the test tube with water and record your observations. 3. Obtain a piece of calcium metal. Use tweezers to handle the calcium metal. Do not touch the calcium metal with your bare hands. 4. Using the tweezers, place a small piece of calcium metal into the water in the medium test tube. Place the large test tube over the mouth of the medium one. Observe what happens for 30 s. Record your observations. 5. Use the candle to light a wooden splint. 6. Lift the large test tube off the medium tube, keeping the mouth of the large tube facing down. Keep firm hold of the large test tube and be prepared for a reaction. With the large test tube still facing down, bring a lit wooden splint near the mouth of the large test tube. Observe. Put the splint out. Record your observations. 7. Clean up your work area. Make sure to follow your teacher’s directions for safe disposal of materials. Wash your hands thoroughly. Observations:

Procedure Step What did you observe?

Calcium - alone

Water in medium t.t. - alone

Phenolphthalein in t.t. – before reaction

Burning splint in large empty t.t. – before reaction

Calcium in water – beginning of the reaction

Burning splint in test tube – after reaction occurs

Products in test tube – after reaction

Phenolphthalein in t.t. – after reaction

Questions: 1. What was the purpose of testing the large, empty test tube with a burning splint before the reaction? ______

2. Why is it suggested that you must be careful to avoid touching calcium metal? ______3. Provide evidence to prove that one or more new pure substances were produced during this experiment. ______4. What type of gas was produced during this lab? How do you know? ______5. Would the product solution be identified as an acid or a base? Explain. ______6. Where were the waste products disposed of after the reaction? ______