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Types of Chemical Reactions. Synthesis. This type of reaction involves the combination of multiple reactants into a single product Synthesis reactions have a general formula: A + B ➜ AB. Examples. 1. Element + Element ➜ Compound 2Al(s) + 3Cl 2 (g) ➜ 2 AlCl 3 (s)
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Synthesis • This type of reaction involves the combination of multiple reactants into a single product • Synthesis reactions have a general formula: A + B ➜ AB
Examples 1. Element + Element ➜ Compound 2Al(s) + 3Cl2 (g) ➜ 2 AlCl3 (s) 2. Compound + Element ➜ Compound PCl3(l) + Cl2 (g) ➜ PCl5 (s) 3. Compound + Compound ➜ Compound SO2(g) + H2O(l) ➜ H2SO4(aq)
Decomposition • This type of reaction involves the splitting of a single reactant into multiple products • Decomposition reactions have the general formula: AB ➜ A + B
Examples • 1. Compound ➜ Element + Element • 2HI(g) ➜ H2(g) + I2 (g) • 2. Compound ➜ Compound + Element • 2 H2O2(l) ➜ 2H2O(l) + O2 (g) • 3. Compound ➜ Compound + Compound • Ca(OH)2(s) ➜ CaO(s) + H2O(l)
WORK • Worksheet • Page 226 to 227, ALL Practice Problems: • Review Questions: Page 229 #1-10
Single Displacement • This type of reaction involves an element and a compound as reactants • The element displaces (replaces) one of the elements in the compound • cations replace cations, anions replace anions • Single displacement reactions have the general formula: Z + AB ➜ ZB + A
Examples Element + Compound Element + Compound Zn(s) + CuSO4(aq) Cu (s) + ZnSO4(aq) Mg(s) + 2AgNO3 (aq) 2Ag (s) + Mg(NO3)2(aq) Br2(g) + CaI2(aq) I2 (g) + CaBr2(aq) 2 Na(s) + 2 H2O(l) H2 (g) + 2 NaOH(aq) 2 Na + 2 HOH H2 + 2 NaOH
Double Displacement • This type of reaction involves two compounds as reactants • Positive and negative ions in two compounds appear to “change partners” to form two new compounds with no change in oxidation numbers [ie. Copper (II) stays copper (II)]. • Double displacement reactions have the general formula: AB + ZY AY + ZB
Examples Compound + Compound Compound + Compound HCl(aq) + NaOH(aq) NaCl (aq) + H2O(l) 2H3PO4 (aq) + 3 Ca(OH)2 (aq) Ca3(PO4)2 (s) + 6H2O (l) MnS(s) + 2HCl(aq) MnCl2 (aq) + H2S(g)
Neutralization • A neutralization reaction is a special case of double displacement reaction between an Acid and a Base. The products of a neutralization reaction are always water and a salt (ionic compound). • Example: • HCl(aq) + NaOH(aq) HOH + NaCl • Hydrochloric acid + sodium hydroxide water + sodium chloride • H2SO4(aq) + 2KOH 2H2O + K2SO4 • Sulfuric acid + potassium hydroxide water + potassium sulfate • During a neutralization reaction, the hydrogen ion from the acid reacts with the hydroxide ion from the base • H+ + OH- H2O
WORK • Finish Worksheet • Page 233 to 235, ALL Practice Problems • Review Questions: Page 240 #1-12 • Tomorrow: QUIZ & LAB (bring goggles)
Combustion • Combustion is a very rapid reaction of a substance with oxygen to produce compounds called oxides. • We often call this process burning. • The following word equation represents a general combustion reaction: fuel + oxygen oxides + (energy)
Hydrocarbons • Hydrocarbons (compounds with H, C) are the most important fuels that we burn! Gasoline, natural gas (methane), propane, kerosene and matches. • When these burn, the products are mostly CO2 and H2O which are released into the atmosphere. These can contribute to the green house effect.
Burning Propane • Complete combustion • Propane + oxygen carbon dioxide + water C3H8 + 5O2 3CO2 + 4H2O • Incomplete combustion Propane + oxygen carbon dioxide + water + carbon monoxide + carbon 2C3H8 + 7O2 2CO2 + 8H2O + 2CO + 2C
Complete vs. Incomplete Combustion of Hydrocarbons • Complete combustion: • Occurs when the right amount of O2 is available to react with the fuel and all the carbon in the fuel is converted into CO2. • The only products are CO2 and H2O. • Incomplete combustion: • This occurs when there is not enough oxygen available to react with the fuel • four products are produced instead of two: CO2, CO, C, H2O • Carbon monoxide is a colourless, odourless, and poisonous gas that can can combine with the haemoglobin in the blood to starve the body of oxygen and cause death!!! • Carbon is the black residue (soot) that you see in fireplaces.
Combustion of metals • Ca + O2 CaO combustion/synthesis
Combustion of Non-metals • N + O2 NO2 combustion/synthesis