8.2 NOTES Synthesis and Combustion

II. Classifying Chemical Reactions some reactions will fit into more than 1 category

Synthesis reactions; also called composition reactions occurs when 2 or more reactants combine to form one product can be simple (2 elements combine) or more complex (a compound and an element or two compounds) when combining compounds; look for a possible polyatomic ion; complex synthesis rxns can sometimes be thought of as decomposition rxns in reverse; MgO + CO2  MgCO3 - if it is known that metal carbonates produce metal oxides and CO2 then metal oxides and CO2 should be able to produce metallic carbonates

Model: Example:

B. Combustion Reactions Combustion reactions normally involve a substance reacting rapidly with oxygen gas, releasing heat and light. Common; hydrocarbons (compounds containing H and C) burn to produce CO2 and H2O; production of water by reacting H2 and O2; Uncommon: burning of coal yields the following: C + O2  CO2 ; O2 reacts with all reactants! Sb2S3 + O2  Sb2O3 + SO2

Model: CxHy + O2  H2O + CO2 Example: