Inorganic Qualitative Analysis (Acidic radical) Experiments: 6 th, 7 th. Detection of acidic radical [anions] for simple salt

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1 Inorganic Qualitative Analysis (Acidic radical) Experiments: 6 th, 7 th and 8 th Objectives: 1. To understand the rationale and the procedure behind the separation for various cations and anions. 2. To perform qualitative analysis of two unknown solutions that contain various ions (cations and anions) and positively identify these ions using established schemes Detection of acidic radical [anions] for simple salt The acidic radicals for simple salts were divided into 3 groups according how it reacts with strong and diluted acids 1. Dilute HCl group: Salts in this group produce specific gases when react with dil. HCl, Acidic radical of this group: Acidic radicals الشق Symbol Reaction of salt with group reagent Carbonates CO Na 2 CO 3 + 2HCl 2NaCl + H 2 O + CO 2 كربونات Bicarbonates HCO 3 - NaHCO 3 + HCl NaCl + H 2 O + CO 2 بيكربونات Sulphites S -- الكبريتيد FeS + 2HCl FeCl 2 + H 2 S Sulphides SO 3 -- Na 2 SO 3 + 2HCl 2NaCl + H 2 O + SO 2 الكبريتيت Thiosulphates S 2 O 3 -- Na 2 S 3 O 3 + 2HCl 2NaCl + H 2 O + SO 2 +S الثيوكبريتات NaNO 2 + HCl NaCl + HNO 2 Nitrites NO 2-3HNO 2 HNO 3 + 2NO + H 2 O النيتريت 2NO + O 2 2NO 2 Cyanides Cyanates CN - CNO - السيانيد السيانات KCN + HCl KCl + HCN NaCNO + HCl HCNO + 2HO + NaCl Chlorates ClO 3 - HClO 3 HClO 4 + H 2 O+ 2O 2 + Cl 2 الكلورات 1

2 1. Dilute HCl group: 1. Carbonates CO 3 All Carbonates are insoluble in water except those with Alkali metals and ammonium soluble in water To study chemical and nature characteristic of Carbonates start systematically the write down your observations and conclusion on your note book 2

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4 All Bicarbonates are soluble in water. 2. Bicarbonates HCO To study chemical and nature characteristic of Bicarbonates, start systematically, then write down your observations and conclusion on your note book 4

5 3. Sulphites SO To study chemical and nature characteristic of Sulphites, start systematically, then write down your observations and conclusion on your note book 5

6 4. Sulphides S - - To study chemical and nature characteristic of Sulphides, start systematically, then write down your observations and conclusion on your note book 6

7 The precipitate soluble in dil. nitric acid Na 2 S + (CH 3 COO) 2 Pb = PbS + 2CH 3 COONa : into salt solution add drops of sodium hydroxide, color of sodium nitroprusside solution will change into violet color 7

8 5. Thiosulphates S 2 O To study chemical and nature characteristic of Thiosulphates, start systematically, then write down your observations and conclusion on your note book Potassium permanganate from violet to colorless white ppt yellow orange brown black 8

9 6. Nitrites NO 2 - To study chemical and nature characteristic of Nitrites, start systematically, then write down your observations and conclusion on your note book 9

10 Cyanates CNO -, Cyanides CN - -, and Chlorates ClO 3 laboratory course due to high risky. salts are not suitable to study in this 11

11 Student s Name: Experiment No. 6 Laboratory Report: 1. Carbonates CO 3 2. Bicarbonates HCO 3 3. Thiosulphates S 2 O 3 11

12 مثال على طريقة كتابة التقرير يجب االستعانة بالقسم النظري للتجارب المرفقة سابقا SULPHITE SO 3 No. Experiment Observation Conclusion 1 Test: Take a pinch of- mixture and add 2-3 ml of dilute sulphuric acid A colorless and pungent smelling gas evolves May be SO 3 Confirmation.Test: A green color is obtained 2 (a) Take 1-2 ml of soda/water extract; add 2-3 ml of dilute sulphuric acid and few drops of potassium dichromate solution 3Na 2 SO 3 + K 2 Cr 2 O 7 + 4H 2 SO 4 Cr 2 (SO4) 3 (Green color)+ 3Na 2 SO 4 + 4H 2 O + K 2 SO 4 SO 3 Confirmed 12

13 2. Concentrate Sulphuric acid group: Salts of this group does not react with dil. HCl. It reacts with Concentrated Sulphuric acid, these salts include the following acidic radicals: Chlorides الكلوريد - Cl NaCl +H 2 SO 4 NaHSO 4 + HCl 2NaCl +H 2 SO 4 Na 2 SO 4 + 2HCl Bromides Br - البروميد 2KBr+3H 2 SO 4 2KHSO 4 +2H 2 O+SO 2 +Br 2 Iodides I - اليوديد 2KI+3H 2 SO 4 2KHSO 4 +2H 2 O+SO 2 +I 2 Nitrates NO 3-4KNO 3 +4H 2 SO 4 4KHSO 4 +2H 2 O+4NO 2 +O 2 النترات Thiocyanates الثيوسيانات - SCN 2. Concentrate H 2 SO 4 group Caution!: Be careful when you use conc. H 2 SO Chlorides Cl - To study chemical and nature characteristic of Chlorides, start systematically, then write down your observations and conclusion on your note book 13

14 2. Bromides Br - To study chemical and nature characteristic of Bromides, start systematically, then write down your observations and conclusion on your note book 14

15 3. Iodides I - To study chemical and nature characteristic of Iodides, start systematically, then write down your observations and conclusion on your note book 15

16 4. Nitrates NO 3 - To study chemical and nature characteristic of Nitrates, start systematically, then write down your observations and conclusion on your note book 16

17 the Ammonia fumes will turn red litmus paper blue. Thiocyanates SCN -, salts are not suitable to study in this laboratory course due to high risky. 17

18 Student s Name: Experiment No. 7 Laboratory Report: 1. Chlorides Cl - 2. Bromides Br - 3. Iodide I 4. Nitrates NO 3 18

19 3. Miscellaneous group: Salts don't react with conc. H 2 SO 4 acid and dil. HCl, each one in different identification test. Acidic radicals Symbol تفاعل محلول الشق مع كل من AgNO 3, BaCl 2 الشق Sulphates SO K 2 SO 4 +BaCl 2 BaSO 4 +2KCl كبريتات راسب أبيض ال يذوب في حمض HCl أو HNO 3 K 2 SO 4 +2AgNO 3 Ag 2 SO 4 +KNO 3 راسب أبيض Borates B 4 O 7 -- Na 2 B 4 O 7 +3H 2 O+2AgNO 3 2AgBO 2 +2H 3 BO 3 +2NaNO 3 بورات راسب أبيض يذوب في النشادر وحمض الخليك Na 2 B 4 O 7 +3H 2 O+BaCl 2 Ba(BO 2 ) 2 +2H 3 BO 3 +2NaCl راسب أبيض يذوب في الزيادة من كلوريد البار يوم Phosphate s PO Na 3 PO 4 +3BaCl 2 Ba 3 (PO 4 ) 2 + 6NaCl فوسفات راسب أبيض يذوب في HCl أو HNO 3 HPO 4 -- Na 2 HPO 4 +3AgNO 3 Ag 3 PO 4 + 2NaNO 3 +HNO 3 راسب أبيض مصفر يذوب في األحماض والنشادر Arsenates AsO 4 3- Na 3 AsO 4 +3AgNO 3 Ag 3 AsO 4 +3NaNO 3 زرنيخات راسب بني يذوب في هيدروكسيد األمونيوم واألحماض المعدنية 19

20 3. Miscellaneous group: 1. Sulphates SO To study chemical and nature characteristic of Sulphates, start systematically, then write down your observations and conclusion on your note book 21

21 2. Phosphates PO To study chemical and nature characteristic of Phosphates, start systematically, then write down your observations and conclusion on your note book 21

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23 3. Borates B 4 O To study chemical and nature characteristic of Borates, start systematically, then write down your observations and conclusion on your note book AsO and AsO are not suitable to study in this laboratory course due to high risky. 23

24 Student s Name: Experiment No. 8 Laboratory Report: Sulphates SO 4 2. Phosphates PO Borates B 4 O