The document discusses balancing chemical equations. It begins by defining key terms like elements, compounds, and chemical reactions. It then explains the steps to balance chemical equations: 1) Identify reactants and products, 2) List elements, 3) Determine atom counts on each side, 4) Adjust with coefficients so atom counts are equal. Two examples show balancing the equations Na + FeCl2 → NaCl + Fe and NaOH + H2SO4 → Na2SO4 + H2O. A quiz provides balanced and unbalanced equations to identify.

1. SCIENCE 10
Quarter 4

2. BALANCING CHEMICAL
EQUATIONS
Guiroy, Blezy V.

3. UNLOCKING OF TERMS
• Matter
• Pure Substance
• Elements
• Compounds
• Chemical Reaction
• Chemical Equation

4. TERMS
MATTER
- anything that has space
and occupies mass
PURE SUBSTANCE
- sample of matter that has definite
chemical and physical properties.

5. TERMS
ELEMENT
- Simplest from of pure substance
COMPOUND
- pure substance that is made up of
two or more elements bonded chemically

6. MOLECULAR SHAPES
Pure
Substances
Made of one
type of matter
Elements
Made of one
type of atom
Compounds
Made of 2 or
More atoms bonded
together
Homogeneous
one phase
MATTER
Made of Atoms
Has Mass &
takes up Space
Heterogeneous
Made of more
than one phase
Can be separated
Mixtures
Made of
more than one
type of matter
Atom + Atom
= Element
Molecule + Molecule
= Compound
Atom + Atom
= Molecule
Example:
Juice
Examples:
Trail Mix
Salad

7. TERMS
CHEMICAL REACTIONS
- process in which the physical and
chemical properties of the original substances
change as new substances with different
physical and chemical properties are formed.
CHEMICAL EQUATION
- symbolic representation of a chemical
reaction in the form of symbols and chemical
formulas

8. H2 + O2  H2O
H O H2O
Reactant Product
Beginning of
the reaction
Formed after
the reaction

9. H2 + O2  H2O
H O H2O
+ 
H
H
H
H
O
O
O

10. LAW OF CONSERVATION
OF MASS
During chemical reaction, atoms are
neither created nor destroyed. The
number of atoms remains constant
throughout the reaction. Since the
number of atoms doesn’t change, the
mass must remain constant as well.

11. H2 + O2  H2O

12. H2 + O2  H2O
H O H2O
+ 
+ 
H
H
O
O
H
H
O
H
H

13. H2 + O2  H2O
H O H2O
+ 
+ 
H
H
O
O
H
H
O
H
H
H
H
O

14. H2 + O2  H2O
H
H
H
H
O
O H
H
O

15. 2H2 + O2  2H2O
H
H
H
H
O
O H
H
O

16. 2H2 + O2  2H2O
BALANCED EQUATION
+ 
H
H
O
O
H
H
O
H
H
H
H
O

17. 2H2
O2
Na
2H2O

18. Na(NO3)2
2Na(NO3)2
O
O
O
O
O
O
N
N
Na
O
O
O
O
O
O
N
N
Na
O
O
O
O
O
O
N
N
Na

20. Na + FeCl2  NaCl + Fe
When sodium metal reacts with
iron (II) chloride, iron metal and
sodium chloride are formed.

21. Na + FeCl2  NaCl + Fe
Na
Cl
Fe

22. Na + FeCl2  NaCl + Fe
Step 1. Identify the reactant and the product.
Reactant: Na + FeCl2
Product: NaCl+ Fe

23. Na + FeCl2  NaCl + Fe
Step 2. List all the elements found on the
chemical equation
__ Na + __ FeCl2  __ NaCl + __Fe
-Na-
-Fe-
-Cl-

24. Na + FeCl2  NaCl + Fe
Step 3. Identify the number of atoms
present in every element in the
reactant side
__ Na + __ FeCl2  __ NaCl + __Fe
1 -Na-
1 -Fe-
2 -Cl-

25. Na + FeCl2  NaCl + Fe
Step 4. Identify the number of atoms
present in every element in the
product side
__ Na + __ FeCl2  __ NaCl + __Fe
-Na- 1
-Fe- 1
-Cl- 1

26. Na + FeCl2  NaCl + Fe
Step 5. Check if the number of atoms
on both reactant and product side is
the same/balanced
__ Na + __ FeCl2  __ NaCl + __Fe
1 -Na- 1
1 -Fe- 1
2 -Cl- 1

27. Na + FeCl2  NaCl + Fe
Step 6. Write coefficient in each element/compound to
change the number of atoms in an element and check if
the number of atoms on both reactant and product side
is the same/balanced
__ Na + __ FeCl2  2NaCl + __Fe
1 -Na- 1
1 -Fe- 1
2 -Cl- 1

28. Na + FeCl2  NaCl + Fe
Step 6. Write coefficient in each element/compound to
change the number of atoms in an element and check if
the number of atoms on both reactant and product side
is the same/balanced
__ Na + __ FeCl2  2NaCl + __Fe
1 -Na- 1
1 -Fe- 1
2 -Cl- 2

29. Na + FeCl2  NaCl + Fe
Step 6. Write coefficient in each element/compound to
change the number of atoms in an element and check if
the number of atoms on both reactant and product side
is the same/balanced
__ Na + __ FeCl2  2NaCl + __Fe
1 -Na- 2
1 -Fe- 1
2 -Cl- 2

30. Na + FeCl2  NaCl + Fe
Step 6. Write coefficient in each element/compound to
change the number of atoms in an element and check if
the number of atoms on both reactant and product side
is the same/balanced
2Na + FeCl2  2NaCl + Fe
2 -Na- 2
1 -Fe- 1
2 -Cl- 2

31. NaOH + H2SO4  Na2SO4 + H2O
When dissolved sodium hydroxide
reacts with sulfuric acid, aqueous
sodium sulfate and water are
formed.

32. NaOH+ H2SO4  Na2SO4 + H2O

33. NaOH+ H2SO4  Na2SO4 + H2O
Step 1. Identify the reactant and the product.
Reactant: NaOH+ H2SO4
Product: Na2SO4 + H2O

34. NaOH+ H2SO4  Na2SO4 + H2O
Step 2. List all the elements found on the
chemical equation
__ NaOH + __ H2SO4  __ Na2SO4 + __H2O
-Na-
-OH-
-H-
-S-

35. NaOH+ H2SO4  Na2SO4 + H2O
Step 3. Identify the number of atoms
present in every element in the
reactant side
__ NaOH + __ H2SO4  __ Na2SO4 + __H2O
1 -Na-
6 -O-
3 -H-
4 -S-

36. NaOH+ H2SO4  Na2SO4 + H2O
Step 4. Identify the number of atoms
present in every element in the
product side
__ NaOH + __ H2SO4  __ Na2SO4 + __H2O
-Na- 2
-O- 5
-H- 2
-S- 1

37. NaOH+ H2SO4  Na2SO4 + H2O
Step 5. Check if the number of atoms
on both reactant and product side is
the same/balanced
__ NaOH + __ H2SO4  __ Na2SO4 + __H2O
1 -Na- 2
5 -O- 5
3 -H- 2
1 -S- 1

38. NaOH+ H2SO4  Na2SO4 + H2O
Step 6. Write coefficient in each element/compound to
change the number of atoms in an element and check if
the number of atoms on both reactant and product side
is the same/balanced
2 NaOH + H2SO4  Na2SO4 + 2 H2O
2 -Na- 2
5 -O- 5
3 -H- 2
1 -S- 1

39. NaOH+ H2SO4  Na2SO4 + H2O
Step 6. Write coefficient in each element/compound to
change the number of atoms in an element and check if
the number of atoms on both reactant and product side
is the same/balanced
2 NaOH + H2SO4  Na2SO4 + 2 H2O
2 -Na- 2
6 -O- 6
4 -H- 4
1 -S- 1

40. BALANCE
A
B
C

43. QUIZ TIME

44. Test I.
Balanced Unbalanced
1AlBr3 + 6K  3KBr + 2Al
1FeO + 1PdF2  1FeF2 + 1PdO
1P4 + 6Br2  4PBr3
2LiCl + 1Br2  LiBr + 1Cl2
1PbBr2 + 2HCl  2HBr + 1PbCl2

45. Test II.
__ BeCl2 + __ AgNO3  __ Be(NO3)2 + __AgCl

46. QUIZ TIME

47. Test I.
Balanced Unbalanced
1AlBr3 + 6K  3KBr + 2Al
1FeO + 1PdF2  1FeF2 + 1PdO
1P4 + 6Br2  4PBr3
2LiCl + 1Br2  LiBr + 1Cl2
1PbBr2 + 2HCl  2HBr + 1PbCl2

48. Test I.
1FeO + 1PdF2  1FeF2 + 1PdO
1P4 + 6Br2  4PBr3
2LiCl + 1Br2  LiBr + 1Cl2
1PbBr2 + 2HCl  2HBr + 1PbCl2
Balanced Unbalanced
1AlBr3 + 6K  3KBr + 2Al

49. Test I.
Balanced Unbalanced
1FeO + 1PdF2  1FeF2 + 1PdO 1AlBr3 + 6K  3KBr + 2Al
2LiCl + 1Br2  LiBr + 1Cl2
1PbBr2 + 2HCl  2HBr + 1PbCl2

50. Test I.
Balanced Unbalanced
1FeO + 1PdF2  1FeF2 + 1PdO
1P4 + 6Br2  4PBr3
1AlBr3 + 6K  3KBr + 2Al
2LiCl + 1Br2  LiBr + 1Cl2
1PbBr2 + 2HCl  2HBr + 1PbCl2

51. Test I.
Balanced Unbalanced
1FeO + 1PdF2  1FeF2 + 1PdO
1P4 + 6Br2  4PBr3
1AlBr3 + 6K  3KBr + 2Al
2LiCl + 1Br2  LiBr + 1Cl2
1PbBr2 + 2HCl  2HBr + 1PbCl2

52. Test I.
Balanced Unbalanced
1FeO + 1PdF2  1FeF2 + 1PdO
1P4 + 6Br2  4PBr3
1PbBr2 + 2HCl  2HBr + 1PbCl2
1AlBr3 + 6K  3KBr + 2Al
2LiCl + 1Br2  LiBr + 1Cl2

53. Test II.
__ BeCl2 + __ AgNO3  __ Be(NO3)2 + __AgCl

54. Test II.
__ BeCl2 + __ AgNO3  __ Be(NO3)2 + __AgCl
– Be –
– Cl –
– Ag –
– N –
– O –

55. Test II.
__ BeCl2 + __ AgNO3  __ Be(NO3)2 + __AgCl
1 – Be –
2 – Cl –
1 – Ag –
1 – N –
3 – O –

56. Test II.
__ BeCl2 + __ AgNO3  __ Be(NO3)2 + __AgCl
1 – Be – 1
2 – Cl – 1
1 – Ag – 1
1 – N – 2
3 – O – 6

57. Test II.
__ BeCl2 + __ AgNO3  __ Be(NO3)2 + 2AgCl
1 – Be – 1
2 – Cl – 1x2=2
1 – Ag – 1x2=2
1 – N – 2
3 – O – 6

58. Test II.
__ BeCl2 + 2AgNO3  __ Be(NO3)2 + 2AgCl
1 – Be – 1
2 – Cl – 1x2=2
2=2x1 – Ag – 1x2=2
2=2x1 – N – 2
6=2x3 – O – 6

59. Test II.
Balanced Equation:
1BeCl2 + 2AgNO3  1Be(NO3)2 + 2AgCl
or
BeCl2 + 2AgNO3  Be(NO3)2 + 2AgCl

60. THE END!