Predicting Products Lab

Predicting Products Lab
Chemistry 5.0 - Equations
Purpose: The Purpose of this lab is to perform a series of ___________, make careful __________________,
identify _________________, and write ___________________________ to describe the reactions.
Pre-lab Questions:
1. What constitutes a positive test for each of the following gases?
a. oxygen (O2):
b. hydrogen (H2):
c. water vapor (H2O):
d. ammonia (NH3):
e. carbon dioxide (CO2) ______________________________ and/or ____________________________
2. What is the proper way to smell a substance in the lab? _________________________
3. What is the role of a catalyst in a reaction? How can you tell if when a substance serves as a catalyst?
Bunsen burner
graduated cylinder
3 wooden splints
ammonium carbonate
cobalt chloride paper
0.1 M potassium iodide (KI)
copper carbonate (CuCO3)
manganese dioxide (MnO2)
2 pieces of magnesium ribbon
watch glass
test-tube rack
copper turnings
3% H2O2
limewater (Ca(OH)2 solution)
0.1 M lead nitrate (Pb(NO3)2
one-hole rubber stopper glass tube elbow
2.0 M Hydrochloric acid (HCl)
crucible tongs
6 test tubes
test-tube clamp
well plate
Read the procedure for each reaction in its entirety before doing it so that you have the necessary materials to complete the
procedure. Wear goggles and an apron throughout the entire lab. Be sure to tie back long hair. Write detailed observations
in the Chart on page 3. Follow disposal instructions.
Reaction 1: Obtain a jar of Cu powder and a crucible from the lab bench and weigh the empty, clean crucible. Add about
1.00 g of Cu powder and determine the actual mass of copper to the nearest .001 g and record. Place the
crucible on a clay triangle and heat it strongly in a Bunsen burner flame for 5 minutes. Allow the crucible to
cool and weigh it again. Record the initial and final appearances of the copper as well as the masses.
Disposal: after the copper cools, throw it into the trash can – wipe out the crucible with a dry paper towel.
Reaction 2: Obtain a 3 cm piece of magnesium ribbon. Clamp the magnesium with a pair of crucible tongs. Ignite the
magnesium in a Bunsen burner flame and collect the ashes on a watch glass. Do not look directly at the
magnesium while it burns. Disposal: throw ashes in trash can after it has cooled down.
Reaction 3: Obtain another 3 cm piece of magnesium. Add 5-10 mL of 3.0 M hydrochloric acid (HCl) to a small test
tube in a test tube rack. Add the magnesium to the acid. Using a test tube clamp, invert a second test tube
(as shown in the figure below) over the mouth of the reaction test tube and collect the gas being produced.
Keep the test tube inverted and test the collected gas by inserting a flaming splint. Record your results.
Disposal: after the Mg has reacted completely with the HCl, the solution can go down the sink with lots of
Reaction 4: Obtain one scoop of ammonium carbonate, (NH4)2CO3, and place it into a small test tube. Clamp the test
tube and heat it in a Bunsen burner. While the test tube is heating, touch a piece of cobalt chloride paper to
the mouth of the test tube and remove it. Smell the test tube using the proper wafting technique. Hold a
flaming splint in the test tube and record the results of each test. Record. Disposal: any solid remaining in
test tube may be rinsed down the sink with water.
Reaction 5: Measure 10 mL of hydrogen peroxide and add to a test tube. Add a very small quantity (tip of spatula) of
manganese dioxide, MnO2, (catalyst) to the test tube. Hold a glowing splint inside the mouth of the test
tube. Hold a piece of cobalt chloride paper to the mouth of the test tube. Record results. Disposal: place
both into the trash.
Reaction 6: Add 1 drop of potassium iodide, KI, and 1 drop of lead (II) nitrate, Pb(NO3)2, to a watch glass. Record the
results. Disposal: wipe the watch glass with paper towel and throw paper towel in trash. Do not put it into
the sink. Be sure to wash your hands well with soap and water.
Reaction 7: Place two scoops of copper (II) carbonate, CuCO3, into a dry large test tube. Insert a stopper with a glass
bend in the test tube. Clamp the test tube to a ring stand at an angle so that the flame will touch the bottom
of the test tube only. Fill a small test tube approximately half way with limewater. Position this test tube so
that the end of the glass bend is in the test tube and is submerged in the limewater. Light the Bunsen burner
and heat the solid in the large test tube. Observe any changes in the limewater. Disposal: once product
cools, place in the trash can, clean test tube; place limewater into the sink with lots of water.
Test Results
Appearance Before:
Appearance After:
1. Burning Cu
Initial Mass:
Final Mass:
Appearance Before:
2. Burning Mg
Appearance After:
3. Mg and HCl
4. Heating
Flaming splint
5. H2O2
Flaming splint
Glowing splint
6. KI and
7. Heating
1. Complete and Balance each equation using the test results above. Indicate the reaction type (synthesis, S,
decomposition, D, single replacement, SR, double replacement, DR, or combustion, C on the line provided.
Reaction 1:
Reaction 2:
Reaction 3:
Reaction 4:
Reaction 5:
Reaction 6:
Reaction 7:
2. Write complete, balanced equations for each of the following. Identify the type (S, D, SR, DR, C):
______ a. When potassium bromate is heated, it decomposes into potassium bromide and a gas that reignites a
glowing splint.
______ b. Sodium metal reacts violently with water to produce sodium hydroxide and a gas that pops in the
presence of a flame.
______ c. When calcium hydroxide is heated, it decomposes into calcium oxide and a substance that will turn
cobalt chloride paper pink.
______ d. The Bunsen burner uses methane gas, CH4. It burns in the presence of O2 and produces a
substance that will extinguish a flaming splint and a substance that turns cobalt chloride paper pink.
______ e. Iron metal will react with oxygen gas in the air to produce rust, iron (III) oxide.
______ f. When you mix baking soda, sodium bicarbonate, with vinegar, acetic acid, they will react violently
to form sodium acetate, and a gas that extinguishes a burning splint and a substance that turns
colbalt chloride paper pink.
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