Synthesis, Decomposition, and Combustion Flashcards
Categorizing Chemical Reactions
- How we categorize groups of reactions to predict the product
- Synthesis, decomposition and combustion
Combustion
- Substance and oxygen → oxides
- Burning with oxygen
- Does not always have to be CO2 and H2O produced
- Can be classified as synthesis
- State symbols are specific
Complete Combustion
- Burning a hydrocarbon with a plentiful supply of oxygen → complete combustion
- it is the ideal way to burn a fuel because it releases the most energy from the fuel molecules
- Cleansest (less sooty) and hottest (blue) flame
- CH + O2 –> CO2 + H2O
Incomplete Combustion
- Burning a hydrocarbon with a limited supply of oxygen → Incomplete combustion
- Products are Soot/carbon monoxide and carbon dioxide/water
- CH + O –> C + CO + CO2 + H2O
Concerns Related to Incomplete Combustion
- Starting your car indoors, or BBQ can cause carbon monoxide build up as there is limited oxygen
- Waste on energy as only a portion can be used by hydrocarbon
- Chemical in soot are toxic and are a health hazard when inhaled
- Carbon monoxide is toxic when inhaled (silent killer)
Synthesis Reactions
Two or more reactants combine to create a larger, complex product
Metal/Non-Metal and Oxygen → Oxide
- Can not be a complete or incomplete combustion
- There is no hydrocarbon
- Product will be solid
- Al + O2 → Al2O
Do all Metal/Non-Metal and Oxygen → Oxide cross correctly?
- No
- You need to draw Lewis structure and see bonds
- 2 S (s) + 3 O2 (g) → 2 SO3 (g)
- C (s) + O2 (g) → CO2 (g)
- Si (s) + O2 (g) → SiO2 (s)
Metal + Non-Metal → Binary Ionic Compound
- Criss cross charges for product
- 2 Al (s) + 3 S (s) → 2 Al2S3 (s)
- Be (s) + Cl2 (g) → BeCl2 (s)
Metal Oxide + Water → Base (Metal + OH-)
Take the metal from oxide and criss cross charge with hydroxide
Li2O + H2O –> 2LiOH
APPLICATION: neutralizing acidic rain
- Calcium oxide helps to neutralize effects of acidic rain
- Boats can carry calcium oxide and sprinkled into acidified water (from acid rain)
- Calcium oxide reacts with water and creates base, and acid and base neutralize
- If soil is acidic, we can sprinkle calcium oxide on soil and moist (water) soil will neutralize through base forming
APPLICATION: cleaning product
- in cleaning products, they contain sodium oxide or sodium hydroxide
- Sodium oxide mixes with water when cleaning and creates this common base
Non-Metal Oxide + Water → Oxyacid
- Product will be the criss cross of the polyatomic -ate and hydrogen
- CO2 + H2O –> H2CO3
Nitrogen oxides
- Cars have a catalytic converter
It takes nitrogen monoxide, and does a decomposition reaction - By preventing reaction one, you prevent the rest from happening (catalytic does it very fast to do this)
- Prevents smog from forming
N2 + O2 –> NO
NO + O2 –> NO2
NO2 + H2O –> HNO3
Carbonic acid
- Rain is slightly acid due to this reaction
- CO2 from factories and H2O from ocean
- Can cause ocean acidification
Sulfuric acid
- Sulfur form factories comes in contact with oxygen
- When sulfur dioxide mixes with water it forms acidic rain (environmental problem)
S + O2 –> SO2
SO2 + O2 –> SO3
SO3 + H2O –> H2SO4
Non-Metal Oxide + Metal Oxide → Salt of Oxyacid
- Metal and non metal criss cross to form salt
- Non metal criss crosses as polyatomic ion with -ate
- CO2 + Na2O –> NaCO3
Decomposition Reactions
- One large compound breaks down into two or more substances
- It is the reverse of synthesis reaction
Non-Metal Oxide + Metal Oxide
Salt of Oxyacid
Non-Metal Oxide + Water
Oxyacid
Metal Oxide + Water
Base (Metal + OH-)
Metal + Non-Metal
Binary Ionic Compound
Metal/Non-Metal and Oxygen
Oxide
Oxide
Metal/Non-Metal and Oxygen
Binary Ionic Compound
Metal + Non-Metal
Base (Metal + OH-)
Metal Oxide + Water
Oxyacid
Non-Metal Oxide + Water
Salt of Oxyacid
Non-Metal Oxide + Metal Oxide
