Experiment: Types of Chemical Reaction

Safety . 1. Hydrochloric acid is corrosive and can cause severe injury. If you spill on yourself, immediately ..

flush the affected area with water for 2-3 minutes and notify the teacher. If acid should get into your eyes, begin flushing your eyes with water immediately and continue dOing so for at least 20 minutes. Ifthere is an eye wash apparatus with continuous running water in the laboratory, use it.

2. If acid is spilled on the laboratory bench or on the floor, netltralize the spill with solid sodium bicarbonate, NaHC03, before wiping it up with sponges or paper towels. The acid is neutralized when bubbles of gas no longer form after addition of sodium bicarbonate.

3. Copper(lI) sulfate is an irritant, avoid skin contact with this chemical. Wash your hands thoroughly after use.

4. Lead and copper compounds are poisonous, bio accumulative, and are water pollutants. However, thesrnall quantities used in this experiment will not contribute significantly to environmental pollution. Use as little of these compounds as practical and rinse small surplus amounts down the drain. Wash your hands thoroughly after use of these compounds.

5. Put all wastes in the large beaker provided by your teacher. Never pour it in the sink.

Procedure As you perform the experiment, record your observations in Table 1 found at the procedure section.

1. Iron metal and copper(lI) sulfate solution. To a small test tube add 15 drops copper(lI) sulfate solution. Add X small spatula of iron filings to the solution. Observe the reaction after 5 minutes. Record your observations in Table 1. Discard the contents of the test tube into the waste container provided.

2. Lead(lI) nitrate and potassium iodide. Put 1 ml of lead(lI) nitrate solution in the test tube. Add 5 drops of potassium iodide solution. Record your observations. Discard the contents of the test tube into the waste container provided.

3. Action of heat on copper(lI) sulfate. Put a pea-size crystals of copper(lI) sulfate penta hydrate into a large test tube. Fasten the utility clamp to the upper end of the test tube. Hold the test tube by the clamp so that it is almost parallel to the surface of the laboratory bench. CAUTION: Do not point the mouth of the test tube to anybody. Make observations as you gently heat the crystals in a burner flame for approximately 30 seconds. Heat only the bottom of the tube, where the crystals are. Discard the contents of the test tube into the waste container provided.

4. Magnesium metal and hydrochloric acid. Add 10 drops of 6M HCI to a medium-sized test tube. CAUTION: HCI is corrosive. Place the test tube in a test tube rack. Put several magnesium turnings into the acid solution. If you observe a gas forming test for its identity by holding a lighted matchstick into the solution. Record your observations. Discard the contents of the test tube into the waste container provided.

5. Action of heat on hydrogen peroxide. Put 1 ml 3% hydrogen peroxide to a medium test tube. Use a utility clamp to secure the tube to a ring stand. CAUTION: Do not point the mouth of the test tube to anybody. Make observations as you gently heat the liquid in a burner flame for

Reaction Observation I Reaction Type . 1. Iron and copper(ll) sulfate i

2. Lead(lI) nitrate and potassium iodide I 3. Heated copper(ll) sulfate penta hydrate I

. 4. Magnesium and hydrochloric acid I 5. Heated hydrogen peroxide I

approximately 30 seconds. If you observe a gas forming, test for its identity by holding a lighted matchstick into the solution. Record your observations. Discard the contents of the test tube into the waste container provided.

Table 1. Observations

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Data Analvsi~ 1. Decide which type of reaction is represented by each reaction observed in the experiment.

Record your answers in Table 1. 2. Write a balanced chemical reaction for each of the reaction observed. 3. No combination reactions were described in the procedure section for this experiment. Give an

example of a combination reaction from an experiment you have done in Pisay. Please note the title of the experiment and the year it was done. Write the balanced chemical reaction for the reaction.