Chemistry - acid reactions

• Not all ions/valencies can be found using the Periodic Table
• Elements with multiple valencies


  e.g., iron can be Fe2+ (iron II ions) or Fe3+ (iron III ions)
• Polyatomic ions


  They are made up of 2 or more atoms, e.g., sulfate ions: SO42- or nitrate ions: NO31-
• Acids


  Compounds that can form hydrogen ions (H+) in solution
• Bases


  Metal oxides and metal hydroxides that produce hydroxide ions (OH-) in solution
• Indicators


  Used to determine acid/base
• Acid-base reaction


  Acid + Base --> Salt + Water
• Carbonates and hydrogen carbonates


  Compounds that can neutralise acids
• Acid-carbonate reaction


  Acid + Carbonate --> Salt + Water + Carbon Dioxide
• Acid-carbonate reaction


  • nitric acid + sodium carbonate --> sodium nitrate + water + carbon dioxide
• Acids only react with the more reactive metals, e.g., Mg, Zn, Fe, Ca, Na, K, Co
• Some metals will not react with dilute acids, e.g., Cu, Ag, Au, Hg
• Acid-metal reaction


  Acid + Metal --> Salt + Hydrogen Gas
• Acid-metal reaction


  • hydrochloric acid + sodium --> sodium chloride + hydrogen gas