Hamilton/Rathburn Chemistry Chemical Reactions Hamilton/Rathburn Chemistry
Chemical Reactions Parts of a chemical reaction: Reactants – substances before reaction occurs Products – substances produced by the reaction
Chemical Reactions Reason why reactions occur: Increase in stability for products
Types of Reactions Combination - two substances combine to form new substance A + B AB Ca + Cl2 CaCl2
Types of Reactions Combustion – substance reacts with oxygen A + O2 AO CH4 + O2 CO2 + H2O
Types of Reactions Decomposition – substance breaks into two or more substances AB A + B MnSO4 MnO + SO3
Types of Reactions Single-replacement – uncombined element “trades places” with an element in a compound A +BX AX + B Cd + 2 HCl CdCl2 + H2
Types of Reactions Double-replacement – two binary compounds “trade partners” AX +BY AY + BX CaCO3 + 2 HCl CaCl2 + H2CO3
Types of Reactions Combination - two substances combine to form new substance A + B AB Ca + Cl2 CaCl2
Types of Reactions Combustion – substance reacts with oxygen A + O2 AO CH4 + O2 CO2 + H2O
Types of Reactions Decomposition – substance breaks into two or more substances AB A + B MnSO4 MnO + SO3
Types of Reactions Single-replacement – uncombined element “trades places” with an element in a compound A +BX AX + B Cd + 2 HCl CdCl2 + H2
Types of Reactions Double-replacement – two binary compounds “trade partners” AX +BY AY + BX CaCO3 + 2 HCl CaCl2 + H2CO3
Chemical Equations Diatomic molecule reminder… Hydrogen H2 Nitrogen N2 Oxygen O2 Fluorine F2 Chlorine Cl2 Bromine Br2 Iodine I2
Chemical Equations Can include heat Endothermic – heat, from surroundings, enters the system, has positive heat of reaction (DH) value, reactants have lower potential energy than products
Chemical Equations Can include heat Endothermic – heat, from surroundings, enters the system Exothermic – heat exits the system and goes to surroundings, has negative heat of reaction (DH) value , reactants have higher potential energy than products