2What is a chemical reaction? A chemical reaction is a process in which one or more substances are converted into new substances with different physical and chemical properties. There are five types of chemical reactions.
3Types of chemical reactions 1.) DIRECT COMBINATION REACTIONS (or synthesis reaction) 2.) DECOMPOSITION REACTIONS (or analysis reaction) 3.) SINGLE-REPLACEMENT REACTIONS 4.) DOUBLE-REPLACEMENT REACTIONS 5.) COMBUSTION
41. DIRECT COMBINATION REACTIONS (Synthesis Reactions) In a direct combination reaction, two or more reactants come together to form single product. A + B AB EXAMPLE: 2 Na + Cl2 2 NaCl
52. DECOMPOSITION REACTIONS (Analysis Reactions) A decomposition reaction is a reaction in which a single compound is broken down into two or more smaller compounds or elements. AB A + B EXAMPLE: CaCO3 CaO + CO2
63. SINGLE-REPLACEMENT REACTIONS In a single-replacement reaction, an uncombined element displaces an element that is part of a compound. A + BX AX + B EXAMPLE: Mg + CuSO4 MgSO4 + Cu
74. DOUBLE-REPLACEMENT REACTIONS In a double-replacement reaction, atoms or ions from two different compounds replace each other. AX + BY AY + BX EXAMPLE: CaCO3 + 2 HCl CaCl2 + H2CO3
85. CoMbustion ReactionsAlthough the majority of chemical reactions fit into one of the four categories of chemical reactions, there are many reactions that do not. Combustion reactions are reactions in which something is burned. Oxygen gas will be a reactant in this type of reaction. EXAMPLE: 2Mg + O2 2MgO