reaction化学反应式.ppt

21/10/99 Chemical Reactions Involving Oxygen A chemical change is any change in which a new substance is formed. Evidence: Release of energy as heat and light, change in colour, formation of gas, change in odour, etc. sulfur + oxygen ? sulfur dioxide phosphorus + oxygen ? diphosphorus pentoxide magnesium + oxygen ? magnesium oxide iron + oxygen ? iron(III) oxide Chemical Reactions Involving Oxygen combustion: AB + oxygen ? oxides of A B synthesis: A + B ? C decomposition: AB ? A + B single displacement: A + BC ? AC + B double displacement: AB + CD ? AD + CB Types: Synthesis Example C + O2 Types: Decomposition Example: NaCl Types: Decomposition Example 2HgO Types: Single displacement Example: Zn + CuCl2 Types: Double displacement Example: MgO + CaS Chemical Reactions Involving Oxygen combustion: AB + oxygen ? oxides of A B synthesis: A + B ? C decomposition: AB ? A + B single displacement: A + BC ? AC + B double displacement: AB + CD ? AD + CB Part 1 reactions can be described as both combustion and synthesis Litmus turned red. Non-metal oxides react with water to form acids. Oxygen (O2). A chemical change. If it were a physical change of state it would keep bubbling until it all evaporated (not turn solid) Chemical Reactions Involving Oxygen This is a decomposition reaction potassium chlorate ? potassium chloride + oxygen * O O C + ? O O C O O C O O C O O C O O C O O C O O C O O C O O C O O C O O C O O C O O C O O C O O C General: A + B ? AB General: AB ? A + B ? Cl Na Cl + Na ? O Hg O Hg Hg O O Hg + General: AB ? A + B ? Zn Cl Cl Cu + General: AB + C ? AC + B Cl Cl Zn Cu + General: AB + CD ? AD + CB S O ? Mg Ca + O S Mg Ca + Single displacement Decomposition Synthesis Double displacement Single displacement Double displacement Combustion (and double displacement?) For more lessons, visit *