Types of Reactions

Synthesis Reactions Also known as Direct Combination Reactions 2 or more reactantsone product A + B  AB 2 Na + Cl2  2 NaCl 4 Fe + 3 O2  2 Fe2O3

Synthesis The skinny bird (reactant) and the worm (reactant) combine to make one product, a bigger bird.

Decomposition Reactions A single compound broken down  2 or more smaller compounds or elements Reverse of Synthesis Rxn AB A + B 2 H2O  2 H2 + O2 CaCO3  CaO + CO2 (marble heated can break down)

Decomposition The egg (the reactant), which contained the turtle at one time, now has opened and the turtle (product) and egg shell (product) are now two separate substances.

Single Replacement Reactions An uncombined element displaces an element that is part of a compound. Reactants: one element one compound Products: one element one compound Metals replace hydrogen or metals Nonmetals replace nonmetals A + BX  AX + B Mg + CuSO4  MgSO4 + Cu Cu + 2 AgNO3  Cu(NO3)2 + 2 Ag

Single Replacement Reactions Not all elements can replace all other elements. A more active element will replace a less active element Activity Series (text p288) Metals most active Li ↓ K ↓ Ba Li can replace K or Ba Can Ba replace K?

Single Replacement

Double Replacement Reactions Atoms/Ions from 2 different compounds replace each other Reactants 2 compounds (usually ionic comp) Products 2 compounds AX + BY  AY + BX CaCO3 + 2 HCl  CaCl2 + H2CO3 antacid stomach acid AgNO3(aq) + NaCl(aq)  AgCl(s) + NaNO3(aq)

Double Replacement

Combustion Reactions Hydrocarbon burning Reactants hydrocarbon and oxygen Products carbon dioxide and water CxHy + O2  CO2 + H2O CH4 + O2 CO2 +H2O

Quiz 11-14 1. Aluminum lawn furniture becomes coated with a layer of aluminum oxide when it sits out in the air. 2. Chlorine gas is bubbled through a calcium bromide solution. The solution turns brown, the color of bromine. 3. Lime (CaO) is added to acidic water in a lake, water and salt are formed. 4. Propane is a common household fuel. When burned, water and carbon dioxide are produced. 5. When an electric current is passed through molten potassium bromide, potassium and bromine form.

Write a balanced equation for the reaction. Quiz 11-9 Magnesium reacts with aqueous hydrochloric acid to form magnesium chloride solution and hydrogen gas. Write a balanced equation for the reaction. What type of reaction is it?