Chemical Reactions

Chemical ReactionsScience, Technology, and Society

Mr. CANOVA PERIOD 11

How to Make a Cake

1. Add flour and eggs and milk, put in the oven for 20 minutes at 450oF and you will have yourself a cake.

2. Flour(s) + eggs(s) + milk(l) → cake(s)

1. Word Equation: uses names of the

reactants and products.

Ex: aluminum plus copper (II) chloride yields

aluminum chloride and copper

2. Skeleton Equation: uses chemical

symbols with no relative amounts.

Ex: Al(s) + CuCl2(aq) → AlCl3(aq) + Cu(s)

NOTE!!!!!!!

• Make sure compounds are written properly.

• Remember to put up the charges and use criss-cross method if needed.

• Remember diatomic molecules.

3. Phases:

s - solid phase

l - liquid phase

g - gaseous phase

aq – aqueous phase

(exists in a water solution)

EX: NaCl(aq) = solid NaCl dissolved in H2O

4. Balanced Formula Equation: shows the relative amounts of the atoms on each side of the equation.

EX: 2Al(s) + 3CuCl2(aq)→ 2AlCl3(aq) + 3Cu(s)

LAW OF CONSERVATION OF MATTER

• To balance equations use ONLY coefficients.

• NEVER, NEVER change a subscript

NOTE!!!!!!!

Balancing Reactions

Types of Reactions

1. Combination (Synthesis)

2. Decomposition

3. Single Replacement

4. Double Replacement

5. Combustion

1. Combination (Synthesis):

Ex: A + B → AB

Ex: 2H2 + O2 → 2H2O

2.Decomposition:

Ex: AB → A + B

Ex: 2H2O → 2H2 + O2

(electrolysis)

3.Single Replacement:

Ex: A + BC → C + BA

Ex: Zn + Cu(NO3)2 → ?

Like replaces likeUSE ACTIVITY SERIES

Is Zn higher than Cu on the list?

Activity Series of MetalsUse for single replacement Reactions

LiKBaSrCaNa

Mg AlMn

Zn Zn + Cu(NO3)2 → Zn(NO3)2 + Cu Fe

CdCoNiSnPbHCuAgHgAu

Decreasing A

ctivity

4.Double Replacement:

Ex: AB + CD → AD + CB

Ex: HCl + NaOH → H(OH) + NaCl

5.Combustion:

Ex: hydrocarbon + O2 → CO2 + H2O

Ex: CH4 + 2O2 → CO2 + 2H2O

This is an example of complete combustion.