Analysis: Chemistry Salt
Chemistry Salt Analysis Cheatsheet
Version 2.0
© 2008 Ankur Banerjee All Rights Reserved. Only important stuff for CBSE Class 12th Chemistry practical syllabus has been included, not everything.
2. WE + acidified K2Cr2O7 2 = sol 3 turns green 3. WE + acidified KMnO4 = pink colour of KMnO4 is discharged 4. Sulphide: Colourless gas with a smell of rotten eggs (H2S); turns lead acetate paper black 1. Sodium nitroprusside test: WE + sodium nitroprusside 4 = purple / violet colour 2. Lead acetate test: WE + lead acetate 5 (aq) = black ppt 5. Nitrite: Pungent light brown gas 1. Starch-iodide test: WE + dil H2SO4 (or dil acetic acid); boil, then add solid KI + fresh starch sol = deep blue colouration Group II (conc H2SO4 group) – Cl(chloride), Br- (bromide), I- (iodide), NO3- (nitrate), CH3COO- (acetate), C2O42(oxalate): Salt + conc H2SO4 1. No reaction: Group II anion not present. Continue to group III. 2. Chloride: Colourless white pungent fumes (HCl); intensify when glass rod dipped in NH4OH is brought near mouth of test tube 1. Silver nitrate test: WE + AgNO3 = white ppt soluble in NH4OH 2. Chromyl chloride test: Salt + solid K2Cr2O7 + 2-3 drops conc H2SO4 = orange / red fumes of chromyl chloride 6 1. Vapours + NaOH (aq) = yellow solution 2. Yellow solution + acetic acid + lead acetate sol = yellow ppt
2 3 4 5 6 Potassium dichromate Solution Na2[Fe(CN)5NO] Pb(CH3COO)2 CrO2Cl2
Anions
Test mentioned next to group is the preliminary test; the ones mentioned under an anion are confirmatory tests for it. Group I (dilute H2SO4 group) – CO32(carbonate), SO32- (sulphite), S2(sulphide), NO2- (nitrite): Salt + dil H2SO4 1. No reaction: Group I anion not present. Continue to group II. 2. Carbonate: Colourless and odourless gas (CO2) 1. WE 1 + MgSO4 = white ppt 3. Sulphite: Colourless gas with pungent smell 1. WE + BaCl2 (aq) = white ppt soluble in dil HCl
1 Water extract: Pinch of salt + water
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3. Bromide: Reddish brown vapour 1. Silver nitrate
Version 2.0
© 2008 Ankur Banerjee All Rights Reserved. Only important stuff for CBSE Class 12th Chemistry practical syllabus has been included, not everything.
2. WE + acidified K2Cr2O7 2 = sol 3 turns green 3. WE + acidified KMnO4 = pink colour of KMnO4 is discharged 4. Sulphide: Colourless gas with a smell of rotten eggs (H2S); turns lead acetate paper black 1. Sodium nitroprusside test: WE + sodium nitroprusside 4 = purple / violet colour 2. Lead acetate test: WE + lead acetate 5 (aq) = black ppt 5. Nitrite: Pungent light brown gas 1. Starch-iodide test: WE + dil H2SO4 (or dil acetic acid); boil, then add solid KI + fresh starch sol = deep blue colouration Group II (conc H2SO4 group) – Cl(chloride), Br- (bromide), I- (iodide), NO3- (nitrate), CH3COO- (acetate), C2O42(oxalate): Salt + conc H2SO4 1. No reaction: Group II anion not present. Continue to group III. 2. Chloride: Colourless white pungent fumes (HCl); intensify when glass rod dipped in NH4OH is brought near mouth of test tube 1. Silver nitrate test: WE + AgNO3 = white ppt soluble in NH4OH 2. Chromyl chloride test: Salt + solid K2Cr2O7 + 2-3 drops conc H2SO4 = orange / red fumes of chromyl chloride 6 1. Vapours + NaOH (aq) = yellow solution 2. Yellow solution + acetic acid + lead acetate sol = yellow ppt
2 3 4 5 6 Potassium dichromate Solution Na2[Fe(CN)5NO] Pb(CH3COO)2 CrO2Cl2
Anions
Test mentioned next to group is the preliminary test; the ones mentioned under an anion are confirmatory tests for it. Group I (dilute H2SO4 group) – CO32(carbonate), SO32- (sulphite), S2(sulphide), NO2- (nitrite): Salt + dil H2SO4 1. No reaction: Group I anion not present. Continue to group II. 2. Carbonate: Colourless and odourless gas (CO2) 1. WE 1 + MgSO4 = white ppt 3. Sulphite: Colourless gas with pungent smell 1. WE + BaCl2 (aq) = white ppt soluble in dil HCl
1 Water extract: Pinch of salt + water
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3. Bromide: Reddish brown vapour 1. Silver nitrate