TYPES OF CHEMICAL REACTIONS
INTRODUCTION:
In this experiment you will perform five different chemical reactions and
your trusty chem teacher will demonstrate two. You will make observations with
an eye towards figuring out what some of the products are. From your
observations, you will identify the type of reaction and write balanced chemical
equations.
PROCEDURE
PART A. STUDENT EXPERIMENTS
1. Iron metal and copper(II) sulfate solution. In a large reaction plate,
add a squirtee of copper(II) sulfate solution. Add a small strip of iron metal to
the solution. Stir occasionally with a toothpick and observe the reaction after 5
minutes. Note both the solution and the solid.
Discard the solid into the inorganic waste container in the hood and the
liquid down the sink.
2. Silver nitrate and sodium chloride solutions. Add several drops of
each reagent to one small well in your reaction plate. Observe. Wash waste down
the sink.
3. Zinc powder metal and hydrochloric acid. Add a squirtee of 6M
hydrochloric acid to another well in a reaction plate. CAUTION: Hydrochloric
acid is corrosive. Add a few sprinkles of the zinc to the acid solution and observe.
Wash waste down the sink.
4. Action of heat on potassium chlorate. In a large pyrex test tube, add
about 1 cm of potassium chlorate crystal. Add a pinch of manganese dioxide as a
catalyst and mix Fasten a utility clamp to the upper end of the test tube. Hold
the tube by the clamp so that it is almost perpendicular to the surface of the lab
bench. CAUTION: Do not point the open mouth of the tube at yourself or the
folks across the bench from you. Make observations as you gently heat the
crystals in the burner flame for approximately 30 seconds. Use the “glowing
splint test” to help you identify one of the products.
When the test tube has cooled, discard its contents in the inorganic waste
container.
5. Action of heat on hydrogen peroxide, H2O2. Add about 5 mL of a 3%
H2O2 solution to a large test tube. Add a small amount of Manganese dioxide to
the solution to act as a catalyst.
Test the identity of the gas evolved by placing a splint with glowing embers
inside the mouth of the tube.
Discard the liquid down the sink.
PART B: TEACHER DEMONSTRATIONS
6. Heating magnesium metal in oxygen.
7. Action of heat on sodium bicarbonate
PROCESSING THE DATA:
1. For each reaction
a. Identify the reaction type: Redox: Combustion, Single replacement,
decomposition or synthesis or formation of a Precipitate (double
replacement).
b. Write a balanced chemical equation for each of the reactions
observed in the lab. Below are some hints. Keep in mind that any elemental
gases formed are diatomic, ie H2 and O2.
Rxn 1: The reddish solid formed is copper, the iron ion in solution is in the
+3 state.
Rxn 2: Don’t dance around and get to the point.
Rxn 3: An invisible ionic zinc salt remains in solution after the reaction.
Rxn 4: One of the products is potassium chloride. Do NOT include the
catalyst as part of the eqation.
Rxn 5: Water is the invisible product. Do NOT include the catalyst as part
of the equation.
Rxn 6: no hints necessary, though this reaction can be classified in two
ways!.
Rxn 7: The salt remaining is sodium carbonate, two different gases were
released.