3rd Nine-Weeks
Week # 02
Chemical Reactions
Chemistry
Balancing Reactions
Vocab:
1. _______Zn +
2. _______Al +
3. _______MgCO3
4. _______Cu2O
_______AgNO3
_______F2


_______AlF3
_______MgO
 _______Cu
_______Zn(NO3)2

+
+
_______CO2
_______O2
+
_______Ag
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Chemical Reactions
5. _______Cl2 + _______LiI
6. ______Ca(NO3)2 +
7. _______C2H6
+

______Na2SO4
_______O2
8. _______NaClO3

9. ______C3H8
_______O2
+
10. ______ Mg(OH)2
_______LiCl

_______NaCl


+
_______I2
 ______CaSO4
_______CO2
+
+
+
______NaNO3
_______H2O
_______O2
_______CO
______ MgO
+
+
_______H2O
______ H2O
2
Chemical Reactions
I. EVIDENCES OF CHEMICAL REACTION
1. bubbling or fizzing, evolution of a gas
2. color change
3. cloudy, formation of a precipitate (an insoluble solid)
4. production of heat and light (does not have to have both)
5. a cloudy solution becomes clear
II. UNDERSTANDING the PARTS of a CHEMICAL REACTION
___ NaCl (aq) +___ H2SO4 (aq) + ___ MnO2 (s)
(g)
[A]
[B]
[C]
___ Na2SO4 (aq) + ___ MnCl2 (aq) +___H2O (l) + ___ Cl2
[D]
[E]
[F]
______________________1. List the reactants.
______________________2. List the products.
______________________3. List the solids.
______________________4. List the gases.
______________________5. List the liquids.
______________________6. List the aqueous (dissolved in water) solutions.
______________________7. What is the mole ratio of sulfuric acid to sodium sulfate?
______________________8. What is the mole ratio of chlorine gas to manganese (IV) oxide?
______________________9. What is the mole ratio of sodium chloride to chlorine gas?
[G]
3
Chemical Reactions
III. Predicting Products
Diatomic Molecules:
Synthesis:
H2, O2, N2, F2, Cl2, Br2, I2 (HON & Halogens)
X + Y = XY
1.
Barium metal reacts with nitrogen gas
2.
Aluminum reacts with sulfur (S8)
3.
Chlorine gas and oxygen gas react to produce dichlorine heptoxide.
Decomposition: XY = X + Y
4. An electric current is applied to molten sodium nitride.
5. An electric current is applied to aluminum oxide.
Combustion:
(a) complete combustion
(sufficient oxygen)
(b) incomplete combustion
(limited oxygen)
CxHy +
O2
CO2
CxHy +
O2
CO
+
+
H2 O
H2 O
6. Butane burns in the presence of sufficient oxygen.
7. Heptane burns in the presence of limited oxygen.
Single Replacement:
metals will take the place of the cation in the compound
halogens will take the place of the halogen in the compound
[remember to use the activity series to determine if the reaction actually works]
Reaction: X + YZ = Y + XZ
4
Chemical Reactions
8. A small piece of potassium metal is dropped into a container of water.
9. A piece of aluminum metal is dropped into a solution of sulfuric acid.
10. A piece of silver metal is dropped into a solution of hydrochloric acid.
11. A piece of magnesium metal is mixed with a solution of aluminum nitrate.
12. A piece of aluminum metal is mixed with a solution of magnesium nitrate.
13. Fluorine gas is bubbled through a solution of lithium iodide.
14. Iodine crystals are dropped into a solution of aluminum chloride.
Double Replacement.
AB
+
CD
AD
+
CB
15. A solution of potassium iodide is mixed with a solution of lead (II) nitrate.
16. A solution of aluminum acetate is mixed with a solution of ammonium sulfate.
17. A solution of barium hydroxide is mixed with a solution of phosphoric acid.
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Chemical Reactions
18. A solution of sodium hydroxide is mixed with a solution of phosphoric acid.
G. Redox Reactions
Definition –
1) To be oxidized mean to have an increase in your oxidation number
2) To be reduced means to have your oxidation number decrease
3) To solve each reaction you must first determine the oxidation number of each element
A. Determining oxidation numbers rules:
1. The oxidation number of an element in its elemental state is ZERO.
2. The oxidation number of a monatomic ion is equal to the charge of the ion.
3. The oxidation numbers of Groups 1 and group 2 in compounds are +1 and +2 respectively
4. The oxidation number of hydrogen is +1 unless it is combined with a metal, in which case it is -1.
5. The oxidation number of oxygen is -2 in most oxygen containing compounds
6. For a compound, the sum of the individual oxidation numbers is zero; for a polyatomic the charge is equal to the sum of
the ion
Ex: (PO4) -3
Ex:
O = -8
FeO + CO
P = +5
Fe + CO2
Find:
A. The substance oxidized
Ex:
3MnO2 + 4Al
B. The substance reduced
2Al2O3 + 3Mn
Find:
A. The substance oxidized
B. The substance reduced
6