Name:
Date:
Block:
Activity: Chemical Reactions
Purpose: To experiment with chemical reactions
To write balanced equations for chemical reactions
Material:
8 test tubes, test tube rack, reagent bottles, magnesium ribbon
Procedure:
i) Please wear safety goggles during this experiment.
ii)Your teacher prepared a number of labelled dropping bottles filled with dilute solutions of
various compounds. For the following steps, you will mix a few mL of each substance in a
test tube.
iii) You need to discard the content of each test tube in a special jar and not down the sink!!.
iv) Clean each test tube using a test tube brush and water.
Clean-up Procedure
Thoroughly rinse out all test tubes, in running water. Invert the test tubes in a test tube rack so
that they dry out for the next group to use them.
Steps:
1. Add a few drops of calcium chloride solution to an equal volume of silver nitrate solution.
Describe what happens in the result table. The products are silver chloride and calcium
nitrate.
2. Add a few drops of calcium chloride solution to an equal volume of sodium carbonate
solution. Describe what happens in the result table. The products are calcium carbonate
and sodium chloride.
3. Add a few drops of sodium bicarbonate solution to an equal volume of acetic acid solution.
Describe what happens in the result table. The products are sodium acetate, water and
carbon dioxide.
4. Add a few drops of copper (II) sulphate solution to an equal volume of sodium hydroxide
solution. Describe what happens in the result table. The products are copper (II) hydroxide
and sodium sulphate.
5. Add a few drops of copper (II)acetate solution to an equal volume of sodium sulphide
solution. Describe what happens in the result table. The products are copper(II) sulfide
and sodium acetate.
6. Add a 1 cm piece of magnesium ribbon to a few drops of dilute sulfuric acid. Describe what
happens in the result table. The products are hydrogen gas and magnesium sulfate.
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7. Add a few drops of potassium chromate solution to an equal volume of barium nitrate
solution. Describe what happens in the result table. The products are potassium nitrate
and barium chromate.
8. Add a few drops of dilute sodium hydroxide solution to a test tube. Add one drop of
phenolphthalein indicator to the same test tube. Now add dilute hydrochloric acid one drop
at a time to the same test tube, until the colour just disappears. The new products are
water and sodium chloride. The acid has « neutralized » the base, and you have made
ordinary common salt or sodium chloride, and water. If time permits, boil away the water.
The film left behind is sodium chloride.
Reagent(Reactant) Bottle collection:
Before you begin your experiment, you need to know the chemicals formula for
each reactants. Using your data booklet, record the chemical formula for each of
the above steps in the following table.
Step
1
2
Reactant #1
CaCl2 (aq)
CaCl2(aq)
3
NaHCO3(aq)
sodium bicarbonate
CuSO4(aq)
Cu(CH3COO)2(aq)
Mg (s)
magnesium ribbon
K2CrO4(aq)
NaOH(aq)
4
5
6
7
8
Reactant #2
AgNO3(aq)
Na2CO3(aq)
sodium carbonate
CH3COOH(aq)
acetic acid
NaOH(aq)
Na2S(aq)
H2SO4(aq)
Ba(NO3)2(aq)
HCl(aq)
Results:
Step
1
2
3
4
Reactants
Calcium chloride,
Silver Nitrate
Calcium chloride,
Sodium carbonate
Sodium bicarbonate,
Acetic acid
Copper(II) sulfate,
Products
Silver chloride (s)
Calcium nitrate (aq)
Calcium carbonate(s)
Sodium chloride(aq)
Sodium acetate(aq),
water(l),
carbon dioxide(g)
Copper(II) hydroxide(s),
Observations
White solid, ppt
(AgCl)
White solid, ppt
(CaCO3)
Bubbles, (gas)
(CO2)
Blue solid, ppt
2
5
6
7
8
Sodium hydroxide
Copper (II) acetate,
Sodium sulphide
Magnesium,
Sulphuric acid
Potassium chromate,
Barium nitrate
Sodium hydroxide,
Hydrochloric acid
Sodium sulfate(aq)
Copper(II) sulphide(s),
Sodium acetate (aq)
Hydrogen(g),
Magnesium sulfate(aq)
Potassium nitrate(aq),
Barium chromate(s)
Water(l),
Sodium chloride(aq)
(Cu(OH)2)
Light blue solid, ppt
(CuS)
Bubbles, gas
(H2)
Yellow solid, ppt
(BaCrO4)
Magenta/pink
becomes clear
(phenolphthalein)
Discussion:
1) For each reaction you carried out, use your data booklet to write the chemical
formulas for the products.
Step
Product #1
Product #2
1
AgCl(s)
Ca(NO3) 2(aq)
2
CaCO3(s)
NaCl(aq)
3
NaCH3COO(aq)
(H2CO3) = CO2(g)+ H2O (l)
4 **
Cu(OH)2(s)
Na2SO4(aq)
5 **
CuS(s)
NaCH3COO(aq)
6 **
H2(g)
MgSO4(aq)
7 **
KNO3(aq)
BaCrO4(s)
8 **
H2O(l)
NaCl(aq)
p.4
2) For each reaction, write the formula equation and then, balance each
equation.
Some reactions produce a gas or a solid called a precipitate(ppt)
(insoluble product). Write (s), (g), (l) or (aq) next to each compound in
the equation. (aq) : aqueous,in solution, dissolved in water
Hints
insoluble (doesn't dissolve well)
Step
1
2
3
Balanced Chemical Equation
CaCl2(aq) + 2 AgNO3(aq) 
CaCl2 (aq) +
Na2CO3 (aq)
2AgCl(s)
2 NaCl (aq)
+ Ca(NO3)2(aq)
+ CaCO3(s)
CH3COOH (aq) + NaHCO3(aq) NaCH3COO(aq) + H2O(l) + CO2(g)
3
2NaOH(aq) Cu(OH)2(s) + Na2SO4(aq)
4
CuSO4(aq)
5
Cu(CH3COO)2 (aq)
6
7
8
Mg(s)
K2CrO4 (aq)
NaOH (aq)
+
+
Na2S(aq)  2NaCH3COO (aq) + CuS(s)
+ H2SO4(aq) 
+ Ba(NO3)2(aq) 
+ HCl(aq) 
MgSO4(aq) + H2(g)
2KNO3(aq) + BaCrO4(s)
NaCl(aq) + H2O(l)
3) Classify each reaction
All are double replacement rxns except for #6 that is a single replacement rxn
Conclusion:
Name three rules for balancing equations
1) Add coefficient in front of the molecules/compounds
2) Cannot change a chemical formula, cannot change subscripts
3) Same number of atoms on either side of the equation
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