Unit 5: Reaction Types Notes

1. Synthesis Reaction

• 2 elements form a larger compoundExample: A + B AB 2Na + Cl2 2 NaCl

* The product is more complex than the reactant

2. Decomposition Reaction

• Reactant breaks apartExample: AB A + B 2H2O 2 H2 + O2

*The reactant is more complex than the products .

3. Combustion Reaction• Anything that burns, Involves a hydrocarbon

and oxygen, Produces Carbon Dioxide and water

***oxygen is always involved in a combustion reaction

Example: CH4 + O2 CO2 + H2O

4. Single Displacement (sometimes called Single Replacement)

• One element of a compound is replaced• “The stud and dud reaction”– The stud is more reactive than the dud.

• Example: A + BX AX + BA is more reactive than B (so A replaces B)Mg +2HCl MgCl2 + H2

B

AX

BX A

5.Double Displacement

• Both compounds switch anions• ** you will always form a gas or a precipitate• Example: AX + BY AY + BX

KI + NaF KF + NaI

6. Acid-Base Reaction

• An acid and a base neutralize each other• There is always an acid (H+) and a Base

(OH-) in the reactants and it always produces water and a salt.

• Example: HCl + NaOH H20 + NaCl