This tackles the basics and the easiest concept of Chemical reactions. This features only the four basic types of chemical reactions: synthesis, decomposition, metathesis, and ion - exchange reaction. This is a basic concept because there is a pattern to be followed in each type of reaction. More types of chemical reactions will be given on my next set of presentation entitled, "Everything You Want to Know About Chemical Reactions."

1. Rajeev G. Bayan
SCIENCE Grade 10

2. The HEART of Chemistry is the concept. on
CHEMICAL REACTIONS.
To understand Chemical Reactions, one must
have to know about Chemical Changes.
What is your idea on Chemical Change?
Chemical Change is simply the change in
composition of a material resulting to the
formation of new substances.

3. The following are Examples of Chemical Changes:

4. Chemical Changes also occur naturally:

5. Chemical Changes involve Chemical Reactions.
What are CHEMICAL REACTIONS?
CHEMICAL REACTIONS show which substances react and which
substances are formed that are easily represented in chemical
formula.

6. Can you still remember how to name chemical formula?
Let’s try!
1. ZnS
2. SnF2
3. SF6
4. CCl4
5. NH3
6. H3BO3 (aq)
7. HBr(aq)
8. Na2CO3•H2O
9. KF•11H2O
10. O2
1. Zinc sulfide
2. Tin (II) fluoride or Stannous fluoride
3. Sulfur hexafluoride
4. Carbon tetrachloride
5. Ammonia or Nitrogen trihydride
6. Boric acid
7. Hydrobromic acid
8. Sodium carbonate monohydrate
9. Potassium fluoride undecahydrate
10. Oxygen gas or Dioxygen

7. Match the description in Column A to the term in Column B.
Column A
1. It is a symbolic representation of a
Chemical Reaction.
2. Reagents involved before Chemical
Reaction.
3. Substances formed after Chemical
Reaction.
4. Represents the number of atoms of
an element in a Compound.
5. Represents the number of moles of a
Compound.
Column B
A. Chemical Equation
B. Coefficient
C. Product
D. Reactant
E. Subscript
F. Yield

8. What happens to the particle during Chemical Reaction?
This is what happens when you turn your stove on.

9. What happens to the particle during Chemical Reaction?
Formation of Water from Hydrogen gas and Oxygen gas.

10. The representation of a chemical
reaction is called CHEMICAL
EQUATION.
In CHEMICAL EQUATION, the reactants
are written on the left side of the arrow
and the products are written on the
right side of the arrow.
This is how we represent the
Combustion of Methane gas.
CH4 + 2O2 ⟶ CO2 + 2H2O

11. In the Chemical Equation, which is/are
the reactants?
CH4 and O2
Which is/are the products?
CO2 and H2O CH4(l) + 2O2(g) ⟶ CO2(g) + 2H2O(g)

12. Aside from reactants and products,
what else is found in the chemical
equation?
Coefficient
The state of the substance
Arrow
Δ
CH4(l) + 2O2(g) ՜
∆
CO2(g) + 2H2O(g)

13. Symbols and what they represent
՜
↔ or ⇌
+
(s)
(l)
(g)
(aq)
՜
∆
𝐇𝟐𝐒𝐎𝟒
Symbols and what they represent
-yield or will produce
-reversible reaction
-separates different subs.
-solid state
-liquid state
-gas state
-aqueous solution
-heat is involved
-catalyst is used (ex. H2SO4)

14. Can you write the Chemical Equation of
the formation of water from the
combination oh Hydrogen gas and
Oxygen Gas?
2H2(g) + O2(g) ⇒ 2H2O(l)

15. Transforming Words into Chemical Equations:
Example:
1. The reaction of Copper and Nitric acid yields Copper (II) nitrate and
Hydrogen gas.
Cu + HNO3 (aq) ⇾ Cu(NO3)2 + H2
2. Aluminum hydroxide neutralizes Hydrochloric acid to form Aluminum
chloride and water.
Al(OH)3 + HCl(aq) ⇾ AlCl3 + H2O

16. Transform the following Chemical Reactions into Chemical Equations:
SET A
1. The combination of Nitrogen gas and Oxygen gas produces Nitrogen
dioxide.
2. When a hot Magnesium metal is combined with Oxygen gas, the result will
be Magnesium oxide.
3. The reaction of Sodium oxide and water yields Sodium hydroxide.
4. When Nitrogen dioxide is added to water, Nitric acid is produced.
5. The combination of Aluminum and Bromine gas will yield Aluminum
bromide.
6. When Calcium oxide reacts with Nitrogen dioxide, the product will be
Calcium nitrate.
7. If Ammonia gas is combined with Hydrogen chloride gas, Ammonium
chloride in solid form will be produced.
8. Carbon dioxide is produced when Carbon combines with Oxygen gas at a
very high temperature.

17. Transform the following Chemical
Reactions into Chemical Equations:
Answers of SET A
1. N2 + O2 ⇾ NO2
2. Mg + O2 ⇾ MgO
3. Na2O + H2O ⇾ NaOH
4. NO2 + H2O ⇾ HNO3
5. Al + Br2 ⇾ AlBr3
6. CaO + NO2 ⇾ Ca(NO3)2
7. NH3 + HCl ⇾ NH4Cl
8. C + O2 ⇾ CO2
What do they have in common?
Yes! They all have 2 or more
REACTANTS but only 1 product.
This type of Chemical Reaction
is called SYNTHESIS or
COMBINATION Reaction.

18. Transform the following Chemical Reactions into Chemical Equations:
SET B
1. At a very high temperature Sodium bicarbonate (or Sodium hydrogen
carbonate) is decomposed into Sodium oxide, Carbon dioxide and Water
vapor.
2. Phosphorous pentachloride is reduced with heat into Phosphorous
trichloride and Chlorine gas.
3. When Ammonium hydroxide is heated, Ammonia gas and water are
evolved.
4. Potassium chlorate is reduced to Potassium chloride and Oxygen gas when
heated.
5. When Sodium chloride pentahydrate is heated, anhydrous Sodium chloride
and Water is produced.
6. When Calcium carbonate heats up, it decomposes into Calcium oxide and
Carbon dioxide.
7. Sodium perchlorate, when heated, decomposes into Sodium chloride,
Dichlorine monoxide and Oxygen gas.

19. Transform the following Chemical
Reactions into Chemical Equations:
Answers of SET B
1. NaHCO3 ⇾ Na2O + CO2 + H2O
2. PCl5 ⇾ PCl3 + Cl2
3. NH4OH ⇾ NH3 + H2O
4. KClO3 ⇾ KCl + O2
5. NaCl•5H2O ⇾NaCl + H2O
6. CaCO3 ⇾ CaO + CO2
7. NaClO4 ⇾ NaCl + Cl2O + O2
What do they have in common?
Yes! They all have 1 REACTANT
and 2 or more products.
This type of Chemical Reaction
is called DECOMPOSITION
Reaction.

20. Transform the following Chemical Reactions into Chemical Equations:
SET C
1. The reaction of Copper and Nitric acid yields Copper (II) nitrate and Hydrogen gas.
2. At a very high temperature, Carbon reacts with water producing Carbon monoxide
and Hydrogen gas.
3. When Potassium Iodide is exposed with Bromine gas, Potassium bromide and
pure Iodine are produced.
4. Copper replaces the metal in Iron (III) chloride and produces Copper (II) chloride
and Iron.
5. When Iron (III) oxide is exposed to Hydrogen gas, Water and Iron metal are
formed.
6. Magnesium replaces the metal in Zinc chloride to produce Magnesium chloride
and Zinc.
7. The reaction of Magnesium to Hydrogen chloride yields Magnesium chloride and
Hydrogen gas.
8. Pure Iron and Carbon dioxide are produced when Carbon displaces the metal in
Iron (III) oxide.

21. Transform the following Chemical
Reactions into Chemical Equations:
Answers of SET C
Cu + HNO3(aq) ⇾ Cu (NO3)2 + H2
2. C + H2O ⇾ CO + H2
3. KI + Br2 ⇾ KBr + I2
4. Cu + FeCl3 ⇾ CuCl2 + Fe
5. Fe2O3 + H2 ⇾ H2O + Fe
6. Mg + ZnCl2 ⇾ MgCl2 + Zn
7. Mg + HCl ⇾ MgCl2 + H2
8. C + Fe2O3 ⇾ CO2 + Fe
This type of Chemical Reaction
is called SINGLE
DISPLACEMENT Reaction.

22. Transform the following Chemical Reactions into Chemical Equations:
SET D
1. Aluminum hydroxide neutralizes Hydrochloric acid to form Aluminum
chloride and water.
2. Silver nitrate and Sodium chloride react and form Silver chloride and
Sodium nitrate.
3. Iron (III) chloride reacts with Sodium hydroxide to produce Iron (III) oxide
and Sodium chloride.
4. Manganese (II) nitrate reacts with Aluminum hydroxide and yields
Manganese (II) hydroxide and Aluminum nitrate.
5. Zinc hydroxide and phosphoric acid neutralize and form Zinc phosphate and
water.
6. The reaction of Ammonium sulfide and Copper (II) nitrate yields Copper (II)
sulfide and Ammonium nitrate.
7. Neutralizing Calcium hydroxide and Sulfuric acid result to Calcium sulfate
and water.

23. Transform the following Chemical
Reactions into Chemical Equations:
Answers of SET D
Al(OH)3 + HCl ⇾ AlCl3 + H2O
2. AgNO3 + NaCl ⇾ AgCl + NaNO3
3. FeCl3 + NaOH ⇾ Fe(OH)3 + NaCl
4. Mn(NO3)2 +Al(OH)3 ⇾ Mn(OH)2 +
Al(NO3)3
5. Zn(OH)2 + H3PO4(aq) ⇾ Zn3(aq) + H2O
6. (NH4)2S + Cu(NO3)2 ⇾ CuS + NH4NO3
7. Ca(OH)2+H2SO4(aq) ⇾ CaSO4 + H2O
This type of Chemical Reaction
is called DOUBLE
DISPLACEMENT Reaction.

24. There are Four Basic Types of Chemical Reactions:
1. SYNTHESIS/ COMBINATION/ COMPOSITION Reaction
2. DECOMPOSITION Reaction
3. METATHESIS/ REPLACEMENT/ SINGLE DISPLACEMENT Reaction
4. ION – EXCHANGE/ DOUBLE DISPLACEMENT Reaction

25. In Synthesis Reaction, two or more simple substances combined to form a
more complex substance.
This can be represented by:
A + B ⇾ AB

26. Synthesis Reaction of Hydrogen gas and Oxygen gas producing Water
This can be represented by:
H2 + O2 ⇾ H2O

27. 1. When a metal reacts with a nonmetal, Binary Compound is produced.
Ex. Mg + Cl ⇾ MgCl2
Na + O2 ⇾ Na2O
2. When a Metal oxide reacts with water, a Metal hydroxide is produced.
Ex. Na2O + H2O ⇾ NaOH
MgO + H2O ⇾ Mg(OH)2
3. When a Nonmetal oxide reacts with water, an Oxyacid is produced.
Ex. NO2 + H2O ⇾ HNO3
SO3 + H2O ⇾ H2SO4
4. When a Metal oxide and a Nonmetal oxide react, a salt is produced.
Ex. Na2O + NO2 ⇾ NaNO3
MgO + SO3 ⇾ MgSO4

28. What will the product be if the
reactants are:
1. Aluminum and Fluorine gas.
2. Silver and Chlorine gas.
3. Hydrogen gas and Oxygen gas.
4. Tin (II) oxide and Water
5. Lead (IV) oxide and Water.
6. Iron(II) oxide and Water.
7. Sulfur dioxide and Water.
8. Nitrogen monoxide and Water.
9. Chromium (II) oxide and Nitrogen
trioxide.
10. Iron (III) oxide and Sulfur dioxide.
ANSWERS
1. Al + F2 ⇾ AlF3
2. Ag + Cl2 ⇾ AgCl
3. H2 + O2 ⇾ H2O
4. SnO + H2O ⇾ Sn(OH)2
5. Pb2O4 + H2O ⇾ Pb(OH)4
6. FeO + H2O ⇾ Fe(OH)2
7. SO2 + H2O ⇾ H2SO3
8. NO + H2O ⇾ HNO2
9. CrO + NO3 ⇾ Cr(NO3)2
10. Fe2O3 + SO2 ⇾ Fe2SO3

29. Decomposition reaction is the opposite of synthesis, where a more
complex substance breaks down to form simpler substances.
This can be represented by
AB ⇾ A + B

30. Decomposition reaction can be brought about by heat, light, electricity and enzymes.
Separating Binary compounds:
Ex. AgCl ՜
∆
Ag + Cl2
MgO ՜
∆
Mg + O2
Heating Carbonates:
Ex. CaCO3 ՜
∆
CaO + CO2
Al2(CO3)3 ՜
∆
Al2O3 + CO2
Heating Bicarbonates:
Ex. NaHCO3 ՜
∆
Na2O + H2O + CO2
Ba(HCO3)2 ՜
∆
BaO + H2O + CO2
Heating Hydrates:
Ex. MgO • 2 H2O ՜
∆
MgO + H2O
Li2O • 102 H2O ՜
∆
Li2O + H2O
Electrolysis in Water
H2O
𝑒𝑙𝑒𝑐𝑡𝑟𝑖𝑐𝑖𝑡𝑦
H2 + O2

31. What will the products be if the given
reactant, when heated, is:
1. Lithium carbonate
2. Aqueous Hydrogen peroxide
3. Aluminum carbonate
4. Mercury (II) oxide
5. Potassium chlorate
6. Magnesium fluoride
7. Silver bicarbonate
8. Sodium sulfide
9. Hydrogen chloride
10. Zinc iodide
ANSWERS
1. Li2CO3 ⇾ Li2O + CO2
2. H2O2 ⇾ H2 + O2
3. Al2(CO3)3 ⇾ Al2O3 + CO2
4. HgO ⇾ Hg + O2
5. KClO3 ⇾ KCl + O2
6. MgF2 ⇾ Mg + F2
7. AgHCO3 ⇾ Ag2O +
CO2+H2O
8. Na2S ⇾ Na + S
9. HCl ⇾ H2 + Cl2
10. ZnI2 ⇾ Zn + I2

32. In SINGLE DESPLACEMENT or REPLACEMENT Reaction, an element
reacts with a Compound replacing one of the element present in the
compound.
The general formula of this
reaction is:
A + BC ⇾ AC + B if A is a metal
or A + BC ⇾ BA + C if A is a
nonmetal

33. Study the examples below:
1. The reaction below shows the tarnishing of Silver.
Ag(s) + H2S(g) ⇾ Ag2S(s) + H2(g)
2. The Silver tarnish can be removed when Aluminum is introduced.
Ag2S(s) + Al(s)
∆,NaHCO3,H2O
Al2S3(s) + Ag(s)
How will you know which element will be replaced or substituted?

34. The Activity Series will
help you predict products
in replacement reactions
and reactivity of metals
with water and acids.

35. More examples below:
Mg + HCl ⇾ MgCl2 + H2
Zn + HCl ⇾ ZnCl2 + H2
Mg + ZnCl2 ⇾ MgCl2 + Zn
Cu + ZnCl2 ⇾ no reaction
Au + FeCl3 ⇾ no reaction
The last two Chemical
equations cannot form
products. Why do you think
so?
Copper has lower reactivity
than Zinc.
Gold has lower activity than
Iron

36. What will the products be if the given
reactants are:
1. Magnesium and Aluminum
fluoride
2. Magnesium metal and Water
3. Carbon disulfide and chlorine gas
4. Hydrogen gas and Iron (III) oxide
5. Nickel and Calcium fluoride
6. Aluminum and Mercury (II)
chloride
7. Platinum and Lithium bromide
8. Potassium and Sodium chloride
9. Cobalt and Hydrofluoric acid
10. Zinc and Sulfuric acid
ANSWERS
1. Mg + AlF3 ⇾ MgF2 + Al
2. Mg + H2O ⇾ MgO + H2
3. CS2 + Cl2 ⇾ CCl4 + S
4. H2 + Fe2O3 ⇾ no reaction
5. Ni + Ca F2 ⇾ no reaction
6. Al + HgCl2 ⇾ AlCl3+ Hg
7. Pt + LiBr ⇾ no reaction
8. K + NaCl ⇾ KCl + Na
9. Co + HF ⇾ CoF2 + F2
10. Zn + H2SO4 ⇾ ZnSO4+ H2

37. Double Displacement or Ion – Exchange Reaction involves switching
places of the Cations and Anions forming new sets of compounds. This
also follows Activity Series of Metals.
The general formula of this
reaction is:
AB + CD ⇾ AD + CB

38. In a Double Displacement Reaction, or ION – EXCHANGE or
METATHESIS, the anions and cations of two compounds switch places to
form new compounds.
Consider the following reactions:
AgNO3 + HCl ⟶ AgCl + HNO3
Na2SO4 + Pb (NO3)2 ⟶ PbSO4 + NaNO3
What do you think are the products of the reaction below?
Ba (NO3)2 + NaOH ⟶ __________________________
Ba(OH)2 + NaNO3

39. Predict the products of the following:
1. FeCl3 + Ca(OH)2
2. Al(OH)3 + H2SO4 (neutralization)
3. BaNO3 + (NH4)2CO3
4. Fe(NO3)3 + Al (OH)3
5. HCl + Mg(OH)2 (neutralization)
NEUTRALIZATION – is a reaction
between an acid an a base
producing salts as the main
product.
Predict the products of the following:
1. FeCl3 + Ca(OH)2 ⟶ Fe(OH)3 + CaCl2
2. Al(OH)3 + H2SO4 ⟶ Al2 (SO4)3 + H2O
3. Ba(NO3)2 + (NH4)2CO3 ⟶ BaCO3 + NH4NO3
4. Fe(NO3)3 + Al (OH)3 ⟶ Fe(OH)3 + Al (NO3)3
5. HCl + Mg(OH)2 ⟶ MgCl2 + H2O

40. CHEMICAL REACTIONS IN THE BODY

41. CHEMICAL REACTIONS IN THE BODY

42. CHEMICAL REACTIONS IN THE ENVIRONMENT

43. THAT’S ALL!