SCH3U- DAY 4

CHAPTER 3- Synthesis, Decomposition and

Combustion Reactions

LEARNING GOALS

• I will learn about chemical equations, reactants and products

• I will review how to balance equations

• I will learn about different synthesis and decomposition rxns

• I will learn about various combustion reactions

• I can predict products of reactions and write balanced equations

• I can predict the products of combustion

• I can explain the difference between complete/incomplete combustion

SUCCESS CRITERIA

CHEMICAL REACTIONS

CHEMICAL EQUATIONS

• Chemical reaction: when elements or compounds react to

form new substances

reactants products

CHEMICAL EQUATIONS

• Chemists use these to show what is happening in the

reaction

• Word equation: uses names of reactants/products

Don’t give key information Too long!

REVERSIBLE REACTIONS

• Can go both ways!

SKELETON EQUATION

• Just has the chemical formulas

• Not balanced!

• Solid sodium metal reacts with liquid water to form an aqueous solution of sodium

hydroxide and hydrogen gas.

• Sulfur trioxide gas reacts with liquid water to form an aqueous solution of sulfuric

acid.

BALANCED EQUATION

• Includes coefficients (numbers of each particle)

• Have discussed previously

BALANCING

SYNTHESIS AND DECOMPOSITION

SYNTHESIS AND DECOMPOSITION

• Opposites of

each other

SYNTHESIS REACTIONS

•A + B -> AB

+

SYNTHESIS REACTIONS

WHAT TO LOOK FOR

• One product formed

• Example: acid rain!

SYNTHESIS

• Three types:

• 1) element + element -> compound

• 2) An element + compound -> compound

• 3) compound + compound -> compound

ELEMENT + ELEMENT -> COMPOUND

• Metal + non-metal -> ionic compound

• Remember ionic compound charges should balance out!

• Nonmetal + non-metal -> compound

• Crisscross doesn’t always work! Can combine in different

ways!

NON-METAL OXIDE + WATER

• Non-metal oxide + water makes ACID • Metal oxide + water makes BASE

DECOMPOSITION

DECOMPOSITION REACTIONS

•AB -> A + B

+

TYPES OF DECOMPOSITION

• Binary compound -> becomes elements

• Metal nitrate -> metal nitrite and oxygen gas

• Metal carbonate -> metal oxide and carbon dioxide

• Metal hydroxide -> metal oxide and water

BINARY COMPOUND DECOMPOSING

• Usually need to use energy to split it up

METAL NITRATE -> METAL NITRITE + 02

• NaNO3

• Usually won’t split up into Na, N, O

• Will be METAL NITRITE and O2

• NaN03 -> NaN02 + 02

METAL CARBONATE -> METAL OXIDE + C02

• CaC03

• Will be metal oxide and CO2

• CAC03 -> CaO + C02

METAL HYDROXIDE -> METAL OXIDE + H20

• Ca(OH)2

• Will be metal oxide and H20

• CA(OH)2 -> CaO + H20

COMBUSTION

COMBUSTION

• Substance COMBINES WITH OXYGEN and releases energy

as oxides, heat and light

• Hydrocarbon: has just H and C

COMBUSTION OF HYDROCARBONS

1

2

3

IMAGE SOURCES

• http://3.bp.blogspot.com/-

AzAqmzU_PKw/U5X8ctYK9UI/AAAAAAAAIQs/js0WjwZnDn8/s1600/stressed-smiley.png

• http://consumerchempd6chemicalreactions.wikispaces.com/file/view/synthesis_cartoon.jpg/68264

843/779x567/synthesis_cartoon.jpg

• http://image.slidesharecdn.com/typesofchemicalreactions-140211080416-phpapp02/95/types-of-

chemical-reactions-11-638.jpg

• https://img.youtube.com/vi/bQJvbmHD1Lg/hqdefault.jpg

• http://image.slidesharecdn.com/decompositionreactionashutoshxthd-131218044439-

phpapp02/95/decomposition-reaction-3-638.jpg?cb=1387342315

• http://images.slideplayer.com/8/2408641/slides/slide_7.jpg

• http://acidrainlaed.weebly.com/uploads/3/0/5/2/30524436/8590010.jpg?390

• http://www.biochemhelp.com/images/metal-hydroxides.jpg

• https://tse1.mm.bing.net/th?id=OIP.1DgwTI6NrAO5ZV-

R8XczHwEsDf&w=244&h=182&c=7&qlt=90&o=4&pid=1.7

• http://www.blewbury.co.uk/energy/images/electrolysis.gif

• https://d1e4pidl3fu268.cloudfront.net/41ecca4b-9485-436e-b633-

9bcba0c0814f/CombustionHSBO.gif