Group IV, V, and VI Cations PDF

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InsightfulCosmos6375

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Beni-Suef National University

Bassma Hossam Anwar

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chemical analysis cations analytical chemistry inorganic chemistry

Summary

These notes provide a detailed guide to identifying Group IV, V, and VI cations using chemical reactions and procedures. The document includes tables summarizing the properties of each cation group, along with diagrams and flowcharts that outline experimental methods, which are essential for laboratory practice in inorganic chemistry.

Full Transcript

Groups IV, V and VI Cations Presented by: Bassma Hossam Anwar Assistant lecturer in Pharmaceutical Analytical Chemistry Department Cations are classified according to the precipitating reagent into six groups: Group No. members...

Groups IV, V and VI Cations Presented by: Bassma Hossam Anwar Assistant lecturer in Pharmaceutical Analytical Chemistry Department Cations are classified according to the precipitating reagent into six groups: Group No. members Pptn reagent Ppt as Group II A 𝐇𝐠 +𝟐 , 𝐂𝐮+𝟐, 𝐂𝐝+𝟐 , 𝐁𝐢+𝟑 𝟎. 𝟐𝟓𝐍 𝐇𝐂𝐥 + 𝐇𝟐 𝐒 HgS, CuS, CdS, 𝐁𝐢𝟐 𝐒𝟑 𝟏𝟎% 𝐍𝐇𝟒 𝐂𝐥 + Al(𝐎𝐇)𝟑 , Fe(𝐎𝐇)𝟑 Group III 𝐀𝐥+𝟑 ,𝐅𝐞+𝟑 , 𝐂𝐫 +𝟑 𝐍𝐇𝟒 𝐎𝐇 Cr(𝐎𝐇)𝟑 𝟏𝟎% 𝐍𝐇𝟒 𝐂𝐥 + Group IV 𝐍𝐢+𝟐 , 𝐂𝐨+𝟐 , 𝐙𝐧+𝟐 NiS, CoS, ZnS 𝐍𝐇𝟒 𝐎𝐇 + 𝐇𝟐 𝐒 𝟏𝟎% 𝐍𝐇𝟒 𝐂𝐥 + Group V 𝐁𝐚+𝟐 , 𝐂𝐚+𝟐 , 𝐒𝐫 +𝟐 𝐍𝐇𝟒 𝐎𝐇 + Ba𝐂𝐎𝟑 , Sr𝐂𝐎𝟑 , Ca𝐂𝐎𝟑 (NH4)2CO3 Group VI 𝐍𝐇𝟒 + , 𝐌𝐠 +𝟐 No specific reagent No specific ppt Group IV Cations: +𝟐 +𝟐 +𝟐 (𝐙𝐧 ,𝐂𝐨 ,𝐍𝐢 ) The precipitating reagent is 10% 𝐍𝐇𝟒 𝐂𝐥 + 𝐍𝐇𝟒 𝐎𝐇 + 𝐇𝟐 𝐒 Scheme for identification of a mixture of group IV cations (𝐙𝐧+𝟐 , 𝐂𝐨+𝟐 , 𝐍𝐢+𝟐 ) 1) In a beaker → Powder + 𝐇𝟐 𝐎 → If not dissolve, heat → If not dissolve, add c. HCL drop wise and heat → then cool 2) Add 10% 𝐍𝐇𝟒 𝐂𝐥 + NH4OH till alkaline + 𝐗𝐬𝐬 𝐇𝟐 𝐒 3) Ppt of mix. of gp IV (𝐙𝐧+𝟐 , 𝐂𝐨+𝟐 , 𝐍𝐢+𝟐 ) White ppt → black ppt → ZnS NiS and CoS White ppt of ZnS Black ppt of CoS and NiS 3) Ppt of mix. of gp IV (𝐙𝐧+𝟐 , 𝐂𝐨+𝟐 , 𝐍𝐢+𝟐 ) 4) Add 1M HCl → shake on cold for 2 mins (only ZnS ppt will be dissolved), then centrifuge ppt Solution (𝐙𝐧+𝟐 ) (𝐍𝐢+𝟐 , 𝐂𝐨+𝟐 ) Test for (𝐙𝐧+𝟐 ) Solution + acetic acid drop wise till acidity + K-ferrocyanide → sky blue ppt 5) ppt (𝐍𝐢+𝟐 , 𝐂𝐨+𝟐 ) + c. HCl + dps 𝐇𝟐 𝐎𝟐 → boil till dissolve and no O2 bubbles, cool, then divide into 2 test tubes 1) test for 𝐂𝐨+𝟐 (vogal’s Rx) 2) Test for 𝐍𝐢+𝟐 Solution + Sn𝐂𝐥𝟐 + dil. H2SO4 Solution + 𝐍𝐇𝟒 𝐂𝐥 solution + ether + 𝐍𝐇𝟒 𝐒𝐂𝐍 solid → + 𝐍𝐇𝟒 𝐎𝐇 till alkaline, shake then cool + DMG ↓ ↓ Blue color in ether (upper) Cherry red ppt layer, So we have 𝐂𝐨+𝟐 So we have 𝐍𝐢+𝟐 Group V Cations: +𝟐 (𝐁𝐚 , +𝟐 +𝟐 𝐒𝐫 ,𝐂𝐚 ) The precipitating reagent is 𝟏𝟎% 𝐍𝐇𝟒 𝐂𝐥 + 𝐍𝐇𝟒 𝐎𝐇 + (𝐍𝐇𝟒 )𝟐𝐂𝐎𝟑 Scheme for identification of a mixture of group V cations (𝐁𝐚+𝟐 , 𝐒𝐫 +𝟐 , 𝐂𝐚+𝟐 ) 1) In a beaker → Powder + 𝐇𝟐 𝐎 → If not dissolve, heat → If not dissolve, add c. HCL drop wise and heat, then cool 2) Add 10% 𝐍𝐇𝟒 𝐂𝐥 + NH4OH till alkaline + 𝐗𝐬𝐬 (𝐍𝐇𝟒 )𝟐𝐂𝐎𝟑 3) Ppt of mix. of gp V (𝐁𝐚+𝟐 , 𝐒𝐫 +𝟐 , 𝐂𝐚+𝟐 ) White ppt of Ba𝐂𝐎𝟑 , Sr𝐂𝐎𝟑 , Ca𝐂𝐎𝟑 White ppt of Ba𝐂𝐎𝟑 , Sr𝐂𝐎𝟑 , Ca𝐂𝐎𝟑 3) Ppt of mix. of gp V (𝐁𝐚+𝟐 , 𝐒𝐫 +𝟐 , 𝐂𝐚+𝟐 ) 4) Add d𝐢𝐥 𝐚𝐜𝐞𝐭𝐢𝐜 𝐚𝐜𝐢𝐝 → boil till ppt dissolved and no 𝐂𝐎𝟐 eff , then divide into 3 test tubes Test for 𝐁𝐚+𝟐 Test for 𝐒𝐫 +𝟐 Test for 𝐂𝐚+𝟐 solution + K2CrO4 Solution + solution → Solution + (𝐍𝐇𝟒 )𝟐 𝐒𝐎𝟒 → 𝐍𝐇𝟒 -Oxalate → yellow ppt white ppt white ppt Group VI Cations: + +𝟐 (𝐍𝐇𝟒 , 𝐌𝐠 ) Has no specific ppt reagent + 1) Test for NH4 : powder + dil. NaOH → boil → ammonia odour 2) Test for Mg +2 : Salt solution + dil. HCl + N𝑎2 HPO4 → boil → cool → add NH4 OH solution → white crystalline ppt

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