(2.3) TYPES OF CHEMICAL REACTIONS

(p144-147)

Word Equation

A word equation - states what reacts and what is

produced- uses words instead of formulas to

describe a chemical reaction

Chemical Reaction

Reactants- the starting materials in a reaction.

Products- the new materials formed in a reaction.

Chemical Equation

Describes a chemical reaction

reactants products

Note: The symbol () can be read as yields or forms or produces

Word Equation-Examples

Ex 1: magnesium + oxygen magnesium

oxide  what reacts what is

produced (reactants) (products)

Word Equation-Examples

Ex 2:zinc + hydrochloric acid hydrogen + zinc

chloride

what reacts what is produced (reactants) (products)

Demo Time!

1)Magnesium reacts with oxygen2)Copper sulfate decomposes3)Zinc reacts with hydrochloric acid4)Lead nitrate reacts with potassium

iodide5)Ethanol burns

CLASSWORK Worksheet 2.3 (A)-complete and hand in

REMINDERS:Did you complete and hand in ?

- Workbook p 46-52- Worksheet “Periodic Table” Q # 1-11

Chemical Reactions – 4 Types

4 main types of chemical reactions Synthesis Decomposition Single displacement Double displacement

Intro animation (see p145)

1. Synthesis Reactions

Two or more reactants combine to form a new product.

GENERAL CHEMICAL EQUATION (GCE)

Synthesis Reactions-Examples

sodium + oxygen sodium oxide

2 H2 + O2 2 H2O

Synthesis Reaction

Tom Katie Tomcat

2. Decomposition Reactions

A compound is broken down into elements or smaller compounds.

GENERAL CHEMICAL EQUATION (GCE)

DDecomposition Reaction

Ben JenniferBennifer

Decomposition Reactions-Examples

sodium oxide sodium + oxygen

2 H2O 2 H2 + O2

Is each reaction synthesis or decomposition?

1. Ag2CO3 Ag2O + CO2

2. P4 + O2 P4O10

3. Fe + O2 Fe2O3

4. KClO3 KCl + O2

Decomposition

Synthesis

Decomposition

Synthesis

Synthesis

Decomposition

3. Single Displacement Reactions

One element replaces another element to form a new compound.

GENERAL CHEMICAL EQUATION (GCE)

Or

Brad & Jen Angelina JenniferBrangelina

Single Displacement- Examples calcium + hydrogen bromide

calcium bromide + hydrogen

Br2 + 2 KI + 2 KBr + I2

4. Double Displacement Reactions

In a double displacement reaction the metal ions in two compounds switch places…”partner swap”

GENERAL CHEMICAL EQUATION (GCE)

Dawson & Joey

Pacey & Jen Pacey & Joey

Dawson & Jen

Double Displacement- Examples

barium sulfide + potassium iodide barium iodide + potassium sulfide

AgNO3 + KCl AgCl + KNO3

Is it single displacement (SD) or double displacement (DD)?

1. NaBr + Ca(OH)2 CaBr2 + NaOH

2. Pb + H3PO4 H2 + Pb3(PO4)2

3. Li3N + NH4NO3 LiNO3 + (NH4)3N

4. CuSO4 + Al Al2(SO4)3 + Cu

DD

SD

SD

DD

Putting it all together: Which Type of Reactions are the following:

a) H2O H2 + O2

b) SiO2 + HF SiF4 + H2O

c) H2 + O2 H2O

d) Cu + HCl H2 + CuCl2Single

Displacement

DoubleDisplacement

Synthesis

Decomposition

Predict What Gets Made

1. Al + Cl2

2. CuF2 + K

3. MgO

4. CaS + FeN

Pick your answer from this box

Mg Ca3N2 F2 KF2

Cu N2 AlCl2 CaFe

AlF3 FeS O2 SN

Chemical Reactions – 5th Type

Another reaction type is Combustion (also called burning)

The burning of fossil fuels always needs oxygen and will yield predictable products.

Complete combustion: lots of O2

Fuel + oxygen carbon dioxide + water(in general) CxHy + O2 CO2 + H2O CH4 + 2 O2 CO2 + 2 H2O

5. Combustion Reactions

The burning of fossil fuels always requires oxygen and will yield predictable products.

Complete combustion: lots of O2

Fuel + oxygen carbon dioxide + water

CxHy + O2 CO2 + H2OCH4 + 2 O2 CO2 + 2 H2O

Combustion Continued

Incomplete combustion: occurs when there is not enough O2

The products are different than with complete combustion.

CxHy + O2 C + CO + CO2 + H2O

Chemical Reactions – 5 Types

And now a video to summarize:Five Major Chemical Reactions

CLASSWORK

WORKBOOK – complete and hand in p. 53-54

Recall: Chemical Reactions – 5 Types

Types of chemical reactions: Synthesis Decomposition Single displacement Double displacement Combustion

Chemical Formulas The chemical formulas of most elements

are written simply as the symbol in the periodic table

Ex: magnesium, Mg sodium, Na

But there are some elements that contain more than one atom.

For a list, see Table 2.9 p147 or your workbook p55

Chemical Formulas

Textbook p 147

Chemical Equation

From the word equation you can now write a chemical equation:

Ex:a) sodium chloride sodium +

chlorine NaCl Na + Cl2b) hydrogen + oxygen water H2 + O2 H2O

CLASSWORK -complete and hand in

Worksheet 2.3 (B) Workbook – p. 57-59