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Inorganic Qualitative Analysis (Acidic radical)
Experiments: 6th, 7th and 8th
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:
Reaction of salt with group reagent الشق Symbol Acidic radicals
Na2CO3 + 2HCl 2NaCl + H2O + CO2 كربونات CO3- -
Carbonates
NaHCO3 + HCl NaCl + H2O + CO2 بيكربونات HCO3-
Bicarbonates
FeS + 2HCl FeCl2 + H2S الكبريتيد S--
Sulphites
Na2SO3 + 2HCl 2NaCl + H2O + SO2 الكبريتيت SO3--
Sulphides
Na2S3O3 + 2HCl 2NaCl + H2O + SO2+S الثيوكبريتات S2O3--
Thiosulphates
NaNO2 + HCl NaCl + HNO2
3HNO2 HNO3 + 2NO + H2O
2NO + O2 2NO2
NO2 النيتريت-
Nitrites
KCN + HCl KCl + HCN
CN السيانيد -
Cyanides
NaCNO + HCl HCNO + 2HO + NaCl
CNO السيانات -
Cyanates
HClO3 HClO4 + H2O+ 2O2 + Cl2
ClO3 الكلورات -
Chlorates
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1. Dilute HCl group:
1. Carbonates CO3
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
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2. Bicarbonates HCO3- -
All Bicarbonates are soluble in water.
To study chemical and nature characteristic of Bicarbonates, start systematically, then write down your observations and conclusion on your note book
No. Experiment Observation conclusion
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3. Sulphites SO3- -
To study chemical and nature characteristic of Sulphites, start systematically, then write down your observations and conclusion on your note book
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No. Experiment Observation conclusion
4. Sulphides S- -
To study chemical and nature characteristic of Sulphides, start systematically, then write down your observations and conclusion on your note book
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The precipitate soluble in dil. nitric acid
Na2S + (CH3COO)2Pb = PbS + 2CH3COONa
: into salt solution add drops of sodium
hydroxide, color of sodium nitroprusside solution will change into violet color
No. Experiment Observation conclusion
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5. Thiosulphates S2O3- -
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
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6. Nitrites NO2-
To study chemical and nature characteristic of Nitrites, start systematically, then write down
your observations and conclusion on your note book
No. Experiment Observation conclusion
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No. Experiment Observation conclusion
Cyanates CNO-, Cyanides CN-, and Chlorates ClO3- salts are not suitable to study in this
laboratory course due to high risky.
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Student’s Name: ……………………………
Experiment No. 6
Laboratory Report:
1. Carbonates CO3
2. Bicarbonates HCO3
3. Thiosulphates S2O3
No. Experiment Observation conclusion
No. Experiment Observation conclusion
No. Experiment Observation conclusion
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التقريرمثال على طريقة كتابة
يجب االستعانة بالقسم النظري للتجارب المرفقة سابقا
SULPHITE SO3
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 SO3
2
Confirmation .Test:
(a) Take 1-2 ml of soda/water
extract; add 2-3 ml of dilute
sulphuric acid and few drops of
potassium dichromate solution
A green color is obtained
3Na2SO3 + K2Cr2O7 + 4H2SO4
Cr2(SO4)3 (Green color)+ 3Na2SO4
+ 4H2O + K2SO4
SO3
Confirmed
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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:
2. Concentrate H2SO4 group
Caution !: Be careful when you use conc. H2SO4 .
1. Chlorides Cl-
To study chemical and nature characteristic of Chlorides, start systematically, then write
down your observations and conclusion on your note book
NaCl +H2SO4 NaHSO4 + HCl
2NaCl +H2SO4 Na2SO4 + 2HCl Cl الكلوريد
- Chlorides
2KBr+3H2SO42KHSO4+2H2O+SO2+Br2 البروميد Br -
Bromides
2KI+3H2SO42KHSO4+2H2O+SO2+I2 اليوديد I-
Iodides
4KNO3+4H2SO44KHSO4+2H2O+4NO2+O2 النترات NO3-
Nitrates
SCN الثيوسيانات
- Thiocyanates
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No. Experiment Observation conclusion
2. Bromides Br-
To study chemical and nature characteristic of Bromides, start systematically, then write
down your observations and conclusion on your note book
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No. Experiment Observation conclusion
3. Iodides I-
To study chemical and nature characteristic of Iodides, start systematically, then write down
your observations and conclusion on your note book
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No. Experiment Observation conclusion
4. Nitrates NO3-
To study chemical and nature characteristic of Nitrates, start systematically, then write down
your observations and conclusion on your note book
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the Ammonia fumes will turn red litmus paper blue.
No. Experiment Observation conclusion
Thiocyanates SCN-, salts are not suitable to study in this laboratory course due to high risky.
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Student’s Name: ……………………………
Experiment No. 7
Laboratory Report:
1. Chlorides Cl-
2. Bromides Br-
3. Iodide I
4. Nitrates NO3
No. Experiment Observation conclusion
No. Experiment Observation conclusion
No. Experiment Observation conclusion
No. Experiment Observation conclusion
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3. Miscellaneous group:
Salts don't react with conc. H2SO4 acid and dil. HCl, each one in different identification test.
Symbol الشق AgNO3 , BaCl2تفاعل محلول الشق مع كل من Acidic
radicals
K2SO4+BaCl2BaSO4+2KCl كبريتات SO4- -
Sulphates
HNO3أو HClراسب أبيض ال يذوب في حمض
K2SO4+2AgNO3Ag2SO4+KNO3
راسب أبيض
Na2B4O7+3H2O+2AgNO32AgBO2+2H3BO3+2NaNO3 بورات B4O7--
Borates
راسب أبيض يذوب في النشادر وحمض الخليك
Na2B4O7+3H2O+BaCl2Ba(BO2)2+2H3BO3+2NaCl
راسب أبيض يذوب في الزيادة من كلوريد البار يوم
2Na3PO4+3BaCl2Ba3(PO4)2 + 6NaCl فوسفات PO4-- -
Phosphate
s
HNO3أو HClراسب أبيض يذوب في
Na2HPO4+3AgNO3Ag3PO4+ 2NaNO3+HNO3 HPO4--
راسب أبيض مصفر يذوب في األحماض والنشادر
Na3AsO4+3AgNO3 Ag3AsO4+3NaNO3
AsO4 زرنيخات 3-
Arsenates
راسب بني يذوب في هيدروكسيد األمونيوم واألحماض المعدنية
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3. Miscellaneous group:
1. Sulphates SO4- -
To study chemical and nature characteristic of Sulphates, start systematically, then write
down your observations and conclusion on your note book
No. Experiment Observation conclusion
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2. Phosphates PO4- - -
To study chemical and nature characteristic of Phosphates, start systematically, then write
down your observations and conclusion on your note book
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3. Borates B4O7- -
To study chemical and nature characteristic of Borates, start systematically, then write down
your observations and conclusion on your note book
No. Experiment Observation conclusion
AsO3--- and AsO4
--- are not suitable to study in this laboratory course due to high risky.