inorganic qualitative analysis (acidic radical

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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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No. Experiment Observation conclusion

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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


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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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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


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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


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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




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التقريرمثال على طريقة كتابة

يجب الاستعانة بالقسم النظري للتجارب المرفقة سابقا

SULPHITE SO3

No. Experiment Observation Conclusion

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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

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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


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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2. Bromides Br-

To study chemical and nature characteristic of Bromides, start systematically, then write


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3. Iodides I-

To study chemical and nature characteristic of Iodides, start systematically, then write down


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4. Nitrates NO3-

To study chemical and nature characteristic of Nitrates, start systematically, then write down


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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.

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Experiment No. 7

Laboratory Report:

1. Chlorides Cl-

2. Bromides Br-

3. Iodide I

4. Nitrates NO3





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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 لا 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 الأحماض والنشادر

Na3AsO4+3AgNO3 Ag3AsO4+3NaNO3

AsO4 زرنيخات 3-

Arsenates

راسب بني يذوب في هيدروكسيد الأمونيوم والأحماض المعدنية

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3. Miscellaneous group:

1. Sulphates SO4- -

To study chemical and nature characteristic of Sulphates, start systematically, then write



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2. Phosphates PO4- - -

To study chemical and nature characteristic of Phosphates, start systematically, then write


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3. Borates B4O7- -

To study chemical and nature characteristic of Borates, start systematically, then write down



AsO3--- and AsO4

--- are not suitable to study in this laboratory course due to high risky.

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Experiment No. 8

Laboratory Report:

1. Sulphates SO4- -

2. Phosphates PO4- - -

4. Borates B4O7- -




inorganic qualitative analysis (acidic radical

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