3.1.4

• CO3^2- + 2H+ -> CO2 + H2O
• test for carbonate ion: strong acid, collect gas and pass through limewater
• test for sulphate ions: add dilute hydrochloric acid and barium chloride, forms white precipitate
• Ba^2+ + SO4^2- -> BaSO4
• Test for ammonium ions: add sodium hydroxide and warm, test with red litmus paper, and chlorine gas
• ammonium ion positive test: litmus paper turns blue, smalls, chlorine fumes turn white
• NH4^+ + OH^- -> NH3 + H2O
• Anion test order: carbonate, sulfate, halide
• anion: negative ion
• test for halide ions: dissolve in distilled water and add silver nitrate. then add aqueous ammonia
• silver nitrate results: chlorine ions turn white, bromine ions turn cream, iodine ions turn yellow
• silver nitrate and ammonia results: chlorine precipitate dissolves in dilute ammonia, bromine precipitate dissolves in concentrated ammonia, iodine precipitate doesn't dissolve
• positive carbonate test: fizzing / effervescence, limewater turns cloudy