1. Parts of an Equation Types of Reactions
IPC Notes
Parts of an Equation
Types of Reactions

2. What is a chemical reaction?
A chemical reaction is the act of changing substances into new substances.
The products of the reaction have different chemical and physical properties.

3. A Chemical Equation
Instead of writing down the entire sentence “hydrogen reacts with oxygen to form dihydrogen monoxide (water)”, you could write the chemical equation.

4. 2H2 + O2c2H2O
REACTANTS → PRODUCTS

5. 5 Parts of a Reaction
reactants – the substances that exist before a reaction takes place; found on the left side of the equation

6. 5 Parts of a Reaction
products – the substances that exist after a reaction takes place; found on the right side of the equation

7. 5 Parts of a Reaction
subscripts – show the number of atoms in a chemical formula
ex) H2O

8. 5 Parts of a Reaction
coefficients – show the number of formula units in an equation
2H2 + O2 → 2H2O

9. 5 Parts of a Reaction
yield sign – the arrow that separates the reactants from the products

10. Other Symbols in an Equation
(s) = substance is solid
(l) = substance is liquid
(g) = substance is a gas
(aq) = substance is
dissolved in water

11. Other Symbols in an Equation
D = heat
A formula written above or below an arrow means it is a catalyst (a substance that speeds up a reaction without being used up by it.)

12. Types of Reactions Synthesis Decomposition Single replacement
There are 5 types of reactions
Synthesis
Decomposition
Single replacement
Double replacement
Combustion

13. Synthesis Reaction
A synthesis reaction occurs when two or more reactants combine to form a single product.
It will follow the form:
A + B a AB
Example: Fe + S a FeS

14. Decomposition Reaction
A decomposition reaction occurs when one reactant breaks down into two or more products.
It will follow the form:
AB a A + B
Example: CaCO3aCaO+CO2

15. Single Replacement Reaction
One element replaces another element in a compound.
Generally follows the form:
AB + C a A + BC
Example:
Mg+Zn(NO3)2aZn+Mg(NO3)2

16. Double Replacement Reaction
Two compounds create two new compounds as the product.
Generally follows the formula:
AB + CD a AD + CB
Example:
Na2S+Cd(NO3)2aCdS+2NaNO3

17. Combustion Reaction
A compound reacts with oxygen producing energy in the form of heat and light.
Usually, it is a hydrocarbon reacting with oxygen, and the outcome is always carbon dioxide and water.

18. Combustion Reaction
Follows the form:
A + O2 a CO2 + H2O
Example:
CH4 + O2 a CO2 + 2H2O

19. 2Na + 2H2O a 2NaOH + H2
Single Replacement

20. Fe + S a FeS
Synthesis

21. Al(OH)3 + 3NaCl aAlCl3 + 3NaOH
Double Replacement

22. 2PbO2 a 2PbO + 3O2
Decomposition

23. Ba(CN)2 + H2SO4 a BaSO4 + HCN
Double Replacement

24. C3H8 + 5O2 a 3CO2 + 4H2O
Combustion

25. 4Li + O2 a 2Li2O
Synthesis

26. 2Ag + 2HCl a 2AgCl + H2
Single Replacement

27. 2H2O2 a 2H2O + O2
Decomposition

28. C2H2 + O2 a CO2 + H2O
Combustion

29. 2HBr a H2 + Br2
Decomposition

30. CrSO4 + 2AgNO3 a Cr(NO3)2 + Ag2SO4
Double Replacement