फिनॉल के रासायनिक गुण (Chemical properties of Phenol)

फिनॉल के रासायनिक गुण ( Chemical properties of  Phenols )-

फिनॉल की अभिक्रियाएं तीन वर्गों में बांटी जा सकती हैं-

(A) फिनॉलिक समूह के कारण अभिक्रियाएं 

(B) बेंजीन वलय की अभिक्रियाएं

(C) विशिष्ट अभिक्रियाये 

(A) फिनॉलिक समूह के कारण अभिक्रियाएं -

(1) फिनॉल की अम्लीय प्रकृति-

फिनॉल अम्लीय  प्रवृत्ति प्रकट करते हैं| यह नीले लिटमस को लाल कर देते हैं तथा क्षारों से क्रिया करके फिनॉक्साइड या फिनेट  बनाते हैं|

फिनॉल क्षारों से क्रिया करके लवण और जल बनाते हैं

C6H5OH + NaOH -------> C6H5ONa + H2O 

फिनॉल  एल्कोहल से प्रबल अम्ल होते हैं क्योंकि फिनॉल में अनुनाद संरचनाये पाई जाती है|

(2) अमोनिया के साथ क्रिया-

फिनॉल 673 K पर निर्जल जिंक क्लोराइड की उपस्थिति में अमोनिया से क्रिया करके ऐनिलीन बनाती है|

                                ZnCl2

C6H5OH + NH3 ---------------> C6H5NH2 + H2O 

(3) जिंक के साथ क्रिया-

फिनॉल को   जिंक चूर्ण के साथ गर्म करने से ऐरोमैटिक हाइड्रोकार्बन  बनता  है|

                               गर्म 

C6H5OH + Zn  ---------------> C6H6 + ZnO 

(4) अम्ल क्लोराइड से क्रिया (ऐसिलीकरण)-

फिनॉल एसिटिल क्लोराइड (पिरीडीन  की उपस्थिति में) से क्रिया करके एस्टर बनाते हैं|

                                        पिरीडीन  

C6H5OH + CH3COCl  -------------> C6H5COOCH3 + HCl 

 (5) बेंज़ोइल  क्लोराइड से क्रिया (बेंजोइलीकरण)-

फिनॉल को जलीय NaOH की उपस्थिति में  बेंज़ोइल क्लोराइड से क्रिया कराके फेनिल बेंजोएट प्राप्त करते  हैं |

 

                                         NaOH 

C6H5OH + C6H5COCl  ------------> C6H5COOC6H5 + HCl 

* यह क्रिया शॉटन बमन अभिक्रिया कहलाती है |

(B) बेंजीन वलय की अभिक्रियाएं-

फिनॉल इलेक्ट्रॉन स्नेही प्रतिस्थापन अभिक्रियाए देता है| -OH समूह आर्थ्रों तथा पैरा निर्देशक समूह होता है|अतः       -OH समूह एरोमेटिक वलय को इलेक्ट्रॉन स्नेही प्रतिस्थापन के लिए आर्थ्रों तथा पैरा स्थानों पर सक्रिय करता है|

(1) हैलोजनीकरण -

फिनॉल हैलोजनीकरण अभिक्रिया के फलस्वरूप पॉली हैलोजन व्युत्पन्न बनाते हैं| फिनॉल  की जलीय  ब्रोमीन विलयन के आधिक्य  से क्रिया के बाद 2,4,6 ट्राइब्रोमोफिनॉल बनता है|

(2) सल्फोनीकरण -

अभिक्रिया ताप के आधार पर फिनॉल  के सल्फोनीकरण से ऑर्थो(o ) समावयवी  या पैरा समावयवी (p) प्राप्त होते हैं| सामान्यतः निम्न ताप पर o-समावयवी तथा उच्च ताप पर p-समावयवी  प्राप्त होते हैं|

(3) नाइट्रीकरण -

 अभिक्रिया परिस्थितियों के आधार पर फिनॉल विविध नाइट्रो प्रतिस्थापित उत्पाद बनाते हैं| फिनॉल  293 क पर HNO3 के साथ 2 तथा 4 नाइट्रो फिनॉल बनाता है| यह सांद्र H2SO4 की उपस्थिति में सांद्र HNO3 के साथ 2,4,6- ट्राई नाइट्रो फिनॉल  बनाता है|

(4) फ्रीडल - क्राफ्ट्स एल्किलीकरण -

फिनॉल की निर्जल AlCl3 की उपस्थिति में एल्किल हैलाइडों से क्रिया कराने पर एल्किल प्रतिस्थापित फिनॉल  प्राप्त होते हैं| जिनमें सामान्यता p- समावयवी  मुख्य उत्पाद होता है| इस क्रिया को फ्रिडल क्राफ्ट्स एल्किलीकरण कहते हैं|

(C) फिनॉलों की विशिष्ट अभिक्रियाएं-

(1) कोल्बे - श्मिट अभिक्रिया -

इस अभिक्रिया में CO2 गैस को 400 K  तथा 4 से 7 वायुमंडल दाब पर सोडियम फीनेट पर प्रभावित करते हैं तथा तनु HCl  से हम अम्लीकृत करते हैं जिससे सैलिसिलिक अम्ल बनता है| इस विधि का प्रयोग सैलिसिलिक अम्ल के औद्योगिक उत्पादन में किया जाता है|

सैलिसिलिक अम्ल,  2- एसिटॉक्सीबेंजोइक अम्ल (एस्प्रिन) निर्माण के लिए प्रारंभिक पदार्थ है| एस्प्रिन पीड़ाहारी तथा ज्वरनाशी औषधि है|

(2) राइमर - टीमन अभिक्रिया -

340 K  पर जलीय सोडियम या पोटैशियम हाइड्रोक्साइड की उपस्थिति में फिनॉल तथा क्लोरोफॉर्म की क्रिया करा कर जल अपघटन कराने पर 2- हाइड्रोक्सी बेन्ज़ेलडिहाईड (सैलिसिलैलडिहाईड) मुख्य उत्पाद के रूप में प्राप्त होता है| इस अभिक्रिया को राइमर - टीमन अभिक्रिया कहते हैं|

(3) हाइड्रोजनीकरण -

फिनॉल Ni उत्प्रेरक की उपस्थिति में हाइड्रोजनीकरण द्वारा 423-427 K  पर संगत साइक्लोहेक्सेनॉल  देता है|

(4) ऑक्सीकरण -

 फिनॉल  सरलता से ऑक्सीकृत हो जाते हैं| वायु व प्रकाश की उपस्थिति में फिनॉल p-benzoquinone में  ऑक्सीकृत हो जाता है| जो पुनः फिनॉल  के आधिक्य से क्रिया करके लाल रंग का योग उत्पाद बनाता है जिसे फिनोक्विनॉन कहते हैं|

फिनॉलों के भौतिक गुण(Physical properties of Phenols)

फिनॉलों के भौतिक गुण(Physical properties of Phenols)

फिनॉलों के महत्वपूर्ण भौतिक गुण निम्नलिखित हैं-

(1) भौतिक अवस्था(Physical state)-

शुद्ध फिनॉल  रंगहीन द्रव या ठोस होते हैं लेकिन ये  सामान्यतः वायुमंडलीय ऑक्सीकरण द्वारा लाल- भूरे हो जाते हैं|  फिनॉल में लाक्षणिक गंध पाई जाती है जिसे फिनालीय  गंध कहते हैं|

(2) विलेयता(Solubility )-

फिनॉल जल में अल्प विलय होते हैं अधिकांश फिनॉल प्रायोगिक रूप में जल में अविलय होते हैं बेंजीन वलय की  जल विरागी प्रवृत्ति के कारण फिनॉल जल में अविलय होते हैं| जबकि फिनॉल अल्कोहल इथर आदि में विलय होते हैं|

(3) क्वथनांक(Boiling point )-

 फिनॉलों  के क्वथनांक संगत हाइड्रोकार्बनों  तथा हैलोएरिनों  से उच्च होते हैं|

जैसे - C6H5OH का क्वथनांक 455 K 

C6H5Cl का क्वथनांक 405 K 

C6H5Br का क्वथनांक 439 K 

C6H6 का क्वनांक 353 K 

 ऐसा फिनॉलों  में अंतराअणुक  हाइड्रोजन आबंधन  के कारण होता है| 

एल्कोहॉलों के रासायनिक गुण

एल्कोहॉलों के रासायनिक गुण

(Chemical properties of alcohols )-

सामान्यतः एल्कोहॉलों  की क्रियाओं को निम्नलिखित दो  वर्गों में विभाजित किया जाता है-

(A) अभिक्रियायें  जिनमें O-H आबंध का विदलन होता है

(B) अभिक्रियायें  हैं जिनमें C-OH आबंध का विदलन होता है

(A) अभिक्रियायें  जिनमें O-H आबंध का विदलन होता है

(1) धातुओं  के साथ क्रियायें -

ऐल्कोहॉल  सक्रिय धातु जैसे सोडियम, पोटैशियम, कैल्शियम, मैग्नीशियम, एलुमिनियम आदि से क्रिया करके हाइड्रोजन मुक्त करता है तथा निर्मित योगिक ऐल्कॉक्साइड कहलाते हैं|

2CH3OH + 2Na ------> 2CH3ONa +H2

2CH3CH2OH + Mg  ------> (CH3CH2O)2Mg +H2

(2) धात्विक हाइड्राइडों से क्रिया-

अल्कोहल धात्विक  हाइड्राइडों  से क्रिया करके ऐल्कॉक्साइड बनाते हैं तथा हाइड्रोजन गैस मुक्त होती है|

CH3OH + NaH  ------> CH3ONa +H2

CH3CH2OH + NaH  ------> CH3CH2ONa +H2

(3) कार्बोक्सीलिक अम्लों के साथ क्रिया ( एस्टरीकरण )-

अल्कोहल कार्बोक्सीलिक  अम्ल से क्रिया करके एस्टर बनाते हैं| इस प्रक्रिया को एस्टरीकरण कहते हैं| यह उत्क्रमणीय क्रिया होती है तथा इसे उपयुक्त उत्प्रेरक (सांद्र H2SO4, शुष्क HCl गैस आदि) की उपस्थिति में कराते हैं|

CH3-COOH + HOC2H5 <====> CH3-COOC2H5

जब HCl गैस का प्रयोग उत्प्रेरक के रूप में किया जाता है तब यह क्रिया फिशर-स्पीयर एस्टरीकरण कहलाती है|

(4) ग्रिगनार्ड अभिकर्मक के साथ क्रिया-

अल्कोहल ग्रिगनार्ड अभिकर्मक से क्रिया करके एल्केन बनाते हैं|

CH3O-H + C2H5-MgBr -----> C2H6 + Mg(OCH3)Br 

(B) अभिक्रियायें  हैं जिनमें C-OH आबंध का विदलन होता है-

(1) हैलोजन अम्लों की क्रिया-

अल्कोहल हैलोजन अम्ल से क्रिया करके हैलोएल्केन तथा जल बनाते हैं| हैलोजन अम्लों  की क्रियाशीलता का क्रम निम्न है-

HI > HBr > HCl 

(A)  HCl के साथ क्रिया-

कम क्रियाशीलता के कारण 1° तथा 2°अल्कोहलों तथा HCl की क्रिया के लिए कुछ उत्प्रेरक (निर्जल ZnCl2) की आवश्यकता होती है लेकिन 3° अल्कोहलों  की क्रिया के लिए उत्प्रेरक की आवश्यकता नहीं होती है|

CH3CH2OH + HCl   ------> CH3CH2Cl  +H2O 

(B)  HBr  के साथ क्रिया-

प्राथमिक अल्कोहलों के लिए उत्प्रेरक के रूप में सांद्र H2SO4 की सूक्ष्म मात्रा की आवश्यकता होती है जबकि द्वितीयक  तथा तृतीयक  अल्कोहलों  के लिए सांद्र H2SO4 की आवश्यकता नहीं होती है|

                                    सांद्र H2SO4

CH3CH2OH + HBr    ---------------> CH3CH2Br   +H2O 

(C)  HI के साथ क्रिया-

एल्किल आयोडाइड बनते हैं|

CH3CH2OH + HI   ------> CH3CH2I  +H2O 

(2) फास्फोरस हैलाइडों  के साथ क्रिया-

फास्फोरस हेलाइड जैसे- PCl5, PCl3, PBr3 अल्कोहलों  से क्रिया करके संगत हैलोएल्केन या एल्किल हैलाइड बनाते हैं|

CH3CH2OH + PCl5   ------> CH3CH2Cl  + POCl3 + HCl 

 3CH3OH + PCl3   ------> 3CH3Cl  +H3PO3 

(3) थायोनिल क्लोराइड  के साथ क्रिया-

थायोनिल क्लोराइड की पिरीडीन उपस्थिति में अल्कोहल से क्रिया कराने पर क्लोरो एल्केन बनते हैं|

CH3CH2OH + SOCl2   ------> CH3CH2Cl  +HCl + SO2 

(4) अमोनिया के साथ क्रिया-

अल्कोहल तथा अमोनिया की वाष्पों के मिश्रण को 633 K  पर गर्म एलुमिना (Al2O3) पर प्रवाहित करने पर प्राथमिक, द्वितीयक तथा तृतीयक  ऐमीनों का मिश्रण प्राप्त होता है| 

CH3CH2OH + NH3   ------> CH3CH2NH2  +H2O 

CH3CH2NH2 +CH3CH2OH-----> (CH3CH2)2NH  +H2O 

 (CH3CH2)2NH +CH3CH2OH---> (CH3CH2)3N   +H2O 

Nomenclature of Alcohols

     Nomenclature of Alcohols

The naming of alcohols is takes place by several methods (systems) -

(1)Common system-

In this system the naming of alcohol is takes place by adding the word alcohol after the alkyl group.

For example-

 

CH3-OH ====> Methyl alcohol

CH3CH2-OH ====>Ethyl alcohol

Normal, iso , tertiary etc.  Prefixes are added in the nomenclature of isomer alcohols.

For example-

CH3CH2CH2OH ====> n- propyl alcohol

CH3CHOHCH3 =====> isopropyl alcohol

(2) I.U.P.A.C. system-

In this system the naming of alcohol is performed by the word "alkanol".

Rule of IUPAC are as follows-

(a) Choose the -OH bond containing longest Carbon chain.

(b) -e is replaced by the suffix -ol in the corresponding alkane chain.

(c) Numbering of Carbon chain is performed in that manner in which the -OH group containing carbon atom has minimum number.

For example-

CH3-OH ====> Methanol

CH3CH2-OH ====>Ethanol

CH3CH2CH2OH ==>Propane-1-ol

CH3CHOHCH3 ==> Propane-2-ol

Phenols

               Phenols

Phenols are the Hydroxy derivatives of aromatic hydrocarbon. 

When the hydrogen atom is replaced by a hydroxyl group    (-OH) from a benzene ring then phenol is formed.

                    -H

C6H5-H ---------------> C6H5-OH

                  +OH

Phenols are further classified into monohydric, dihydric, trihydric etc. on the basis of the number of hydroxyl group (-OH) which is attached to the benzene ring.

Classification of phenols-

(1) Monohydric phenol-

In this type of phenol only one hydroxyl group (-OH) is attached to the benzene ring.

For example-

C6H5-OH

(2) Dihydric phenol-

In this type of phenol two hydroxyl group (-OH) is attached to the benzene ring.

For example-

C6H4-(OH)2

(3) Trihydric phenol-

In this type of phenol three hydroxyl group (-OH) is attached to the benzene ring.

For example-

C6H3-(OH)3

Corrosion of Metals

        Corrosion of Metals

If a metal is reactive, its surface may be attacked slowly by the air and water ( moisture) in the atmosphere. The metal reacts with the oxygen of air and water vapour of air forming Compounds on its surface. The formation of these compounds tarnishes the metals, that is ,it makes the the surface of metal appear dull. The compounds formed on the surface of metal are usually porus and gradually fall off from the surface of metal, and then the metal underneath is attacked by air and water. This process goes on and on. In this way, the action of air and water gradually eats up the whole metal. At some places ( especially in industrial areas) there are some acidic gases in the air which mix with rain water to form chemicals such as acids. These acids also attack the surface of metals and eat them up slowly.

            The eating up of metals by the action of air, moisture or a chemical ( such as an acid) on their surface is called corrosion. Most of the metals corrode when they are kept exposed to moist air.
For example- Iron metal corrodes when kept in moist air for a considerable time. When an iron object is kept in moist air for a considerable time, then a red-brown substance called rust is formed on its surface. Rust is  soft and porous, and it gradually falls off from the surface of iron object, and then the iron below starts corroding. Thus corrosion of iron is a continuous process which ultimately eats up the whole iron object.
The corrosion of iron is called rusting while other metals are said to corrode, iron metal is said to rust.

                                Rusting of Iron-

When an iron object is left in moist air (or water) for a considerable time, it gets covered with a Red- brown flaky substance called rust. This is called rusting of iron. During the rusting of iron, iron metal combines with the oxygen of air in the presence of water to form hydrated iron(|||) oxide, Fe2O3.xH2O.  This hydrated iron(|||) oxide is called rust. So rust is mainly hydrated iron(|||) oxide,Fe2O3.xH2O.   (The number of molecules of water x varies, it is not fixed). Rust is Red brown in colour. We have all seen iron nails, screws, pipes and railings covered with Red brown rust here and there. It is not only the iron which rusts, even the Steel rust on being exposed to moist air (or on being kept in water). But still rusts less readily than iron .

Conditions necessary for the rusting of iron-

Rusting of iron (or corrosion of iron) needs both air and water.  Thus two conditions are necessary for the rusting of iron to take place: 

(1)  Presence of air (or oxygen) 

(2) Presence of water (or moisture)

We know that iron rusts when placed in moist air or when placed in water. Now, moist air also contains water vapour. Thus, moist air alone supplies both the things, air and water required for the rusting of iron. Again, ordinary water has always some air  dissolved in it. So, ordinary water alone also supplies both the things, air and water needed for rusting.

Prevention of rusting-

The wasting of iron objects due to rusting causes a big loss to the country's economy. So it must be prevented. Several methods are used to protect the iron objects from rusting (or corrosion).  Most of the methods involve coating the iron object with something to keep out air and water (which cause rusting).  The various common methods of preventing the rusting of iron (or corrosion of iron) are given below-

(1) Rusting of iron can be prevented by painting- 

 The most common method of preventing the rusting of iron is to coat its surface with paint. When a coat of paint is applied to the surface of an iron object, then air and moisture cannot come in contact with the iron object and hence no rusting takes place.

(2) rusting of iron can be prevented by applying grease or oil-

When some grease or oil is applied to the surface of an iron object then their and moisture cannot come in contact with it and hence rusting is prevented.

(3) Rusting of iron can be prevented by galvanization-

The process of depositing a thin laye of zinc metal on iron object is called galvanization. Galvanisation is done by dipping and iron object in molten zinc metal. A thin layer of zinc metal is then formed all over the iron object. This thin layer of zinc metal on the surface of iron objects protects them from rusting because zinc metal does not corrode on exposure to moist air.

(4) Rusting of iron can be prevented by tin plating and chromium plating-

Tin and chromium metals are resistant to corrosion. So when a thin layer of tin metal or chromium metal is deposited on iron and Steel objects by electroplating, then the iron and steel objects are protected from rusting.

(5) Rusting of iron can be prevented by alloying it to make stainless steel-

When iron is alloyed with chromium and nickel, then stainless steel is obtained. Stainless steel does not rust at all. Cooking utensils, knives, scissors and surgical instruments etc. are made of stainless steel and do not rust at all.

Chemical bonding and their types

Chemical bonding and their types-

Chemical bond -
A bond is any force which holds two atoms together. The formation of bond between two atoms is due to some redistribution or regrouping of electrons to form a more stable configuration. Several atoms are assembled and held together to form thousands of molecules which participate in the building and function of physical and biological systems.

Types of chemical bond-
The regrouping of electrons in the combining atoms may take place in either of three ways-

(1) Electrovalent or polar or ionic bond======> by a transfer of one or more electrons from one atom to another.

(2) Covalent bond =======> by a sharing of one or more pairs of electrons between the combining atoms.

(3) Co-ordinate Bond =======> by a combination of the two processes of transfer and sharing of electrons.



(1) Electrovalent or polar or ionic bond-

Ionic bond formation takes place between atoms of strongly electropositive and strongly electronegative elements. An element preceding and inert gas in the periodic table is strongly electronegative and the element immediately following the inert gas is strongly electropositive. For example- chlorine is electronegative while sodium is electropositive. According to W. kossel (1916),a transfer of electrons takes place from the outermost shell of the electropositive atom to the outermost shell of the electronegative atom, resulting in the formation of stable positive and negative ions respectively which are held together by electrostatic forces of attraction to form a molecule or more precisely and ion pair .


A   +   B ------> A+  +  B-

The atoms involved are electrically neutral before combining. The element A which has lost its electrons is known as electropositive where as element B which has gained the electrons is termed electronegative element. The compound formed by electron transfer is termed as electrovalent by Langmuir (1919) because the resulting compound is electrolyte. It is also called Polar since the molecules develops a positive and a negative pole.
               The electrovalent compounds always exist in ionic form, are hard and nonvolatile, have high melting and boiling points because of stronger nature of the bond and are soluble in polar solvents and because of the presence of ions conduct electricity in solution or in the fused state. The electrovalent compounds having identical electronic configuration exhibit the phenomenon of isomorphism.

 Na   +   Cl  ---->   Na+    +     Cl-

 Ca   +   O  -----> Ca2+   +   O2-

(2) Covalent bond (Nonpolar Bond)-

Covalent bond formation first suggested by G.N. Lewis (1916) consists in sharing or holding a pair of electrons in partnership between two combining atoms, so that the pair counts towards the electronic grouping of both atoms. By this mechanism also, the stability akin to the inert gas is attained by each atom. For each pair of electrons to be shared between two atoms in each of the constituent atom contributes one electron.

   A•  +   B• ----->  A : B

This type of linkage which is the result of equal contribution and equal sharing of electrons is known as covalent bond. The compound formed by electron sharing is termed as covalent or or nonpolar by Langmuir (1919).
              The covalent compounds always exist in molecular form, are non electrolytes or non ionizable, soluble in organic solvents and have low melting and boiling points because of weaker nature of the bond. They are usually liquids or gases and are generally soft, easily fusible and volatile. They are non conducting in the fused state or in solution. The covalent bond is rigid and directional and as such there is a  possibility of position isomerism and stereoisomerism amongst these compound.
              covalent linkage is common in organic compounds, although inorganic compounds also have it. In covalent compounds one pair of shared electrons corresponds to a single bond, two pairs to double bond, three pairs of electrons or 6 shared electrons to triple Bond.
        Some common examples from three categories are-

 H •  +  H•  ------> H-H

   :            :
 :O:   +   :O:   --------> O=O

                                    _
 N:.  +   .:N   ------>  N=N
                                 

(3) Co-ordinate Bond (Semipolar or Dative Bond)-

Co-ordinate bond is also formed by mutual sharing of electrons but in this case the two electrons that are shared come from the same atom. The shared pair of electrons is called lone pair. The atom which provides the pair of electrons is called the donor and the atom accepting this pair is called the acceptor. After the formation of the bond, the lone pair of electrons is held in common. This sort of bonding is called co-ordinate (Sidgwick) or dative (Menzies). In this mechanism although the sharing is equitable the contribution is one sided and therefore a slight polarity develops in the molecule. For this reason this bond is also called semipolar (Sugden). This type of linkage is represented by an arrow pointing away from the donor atom (or pointing towards the acceptor atom). Usually the donor is an atom which has already acquired stable electronic configuration and the acceptor is generally two short of the stable configuration.

    :         :                  :   :
  :A:  +  B:  ------>   :A:B:
    :         :                  :   :
In this case atom A is dinor and atom B is acceptor because atom A is given a lone pair of electrons to atom B.

For example- In O3(Ozone) form a co- ordinate bond.

   :         :        :              :    :      :
 :O:  + :O: + :O: -----> :O::O:->O:
                                                  :

Trichloromethane (chloroform)

Trichloromethane  (chloroform)      CHCl3

 Trichloromethane is a trichloro derivative of methane. It is commonly called as chloroform.

Methods of preparation-

 It is prepared by the chlorination of methane in the presence of sunlight.
         Sunlight
CH4 -------------------> CH3Cl + HCl
           +Cl2


             Sunlight
CH3Cl ---------------> CH2Cl2+ HCl
                +Cl2


             Sunlight
CH2Cl2 ---------------> CHCl3+ HCl
                  +Cl2           

Properties-

(1) colourless heavy liquid

(2) sweet taste 

(3) it is oxidised in the sunlight and form a harmful gas carbonyl chloride which is commonly called as phosgene.

                    Sunlight
2CHCl3+O2 ---------> 2COCl2+HCl                                           

Phosgene is a very poisonous gas. So it is not used in the anaesthetic purpose.

Process of storage for chloroform-

(1) For the prevent from sunlight chloroform is stored in coloured bottle.
(2) for the prevent from air chloroform is fully filled in the bottle.
(3) before the storage of chloroform in the bottle it is mixed with ethanol 0.6 to 1%. Ethanol reacts with phosgene and form non poisonous diethyl carbonate.

2C2H5OH + COCl2 ------->(C2H5)2CO3  +  2HCl


Uses of chloroform-

(1) it is used as a anaesthetic but its heavy dose is very lethal.
(2) it is used as a solvent for oil,fat ,rubber,raisin etc.
(3) it is used for preparation of chloropicrin ,chloretone etc.
(4) it is used for conservation of animals in the laboratory.
(5) it is used for making medicines.
(6) it is used as a laboratory reagent in the laboratory.
(7) in the present time chloroform is used for making freon refrigerant R-22.

Alcohols

                    Alcohols

Hydrocarbons are the parents of other organic compounds. When One or more hydrogen atoms are replaced by the different types of atoms or group of atoms from hydrocarbons then different types of organic compounds are formed .
           When hydrogen atoms are replaced from saturated aliphatic hydrocarbons by the hydroxyl group (-OH) ,then Alcohols are formed.
  For example-

                -H
  R-H ------------->    R-OH                                +OH

Where R is the alkAl group.

                   -H
 CH3-H ------------->     CH3-OH                         +OH              (Methanol)


So, Hydroxy derivatives of the aliphatic hydrocarbons are known as Alcohols.



Classification of Alcohols-

Hydroxy derivatives of the aliphatic hydrocarbons are known as Alcohols.
The general formula of the alcohols are R-OH. Where R is the Alkyl group.

Alcohols are classified on the basis of the number of the Hydroxyl groups (-OH) attached to the alkAl group.


(1) Monohydric Alcohols -

In the monohydric alcohols only one Hydroxyl group (-OH) attached to the alkAl group. The general formula of the monohydric alcohols are CnH2n+1OH or ROH.
   These are further classified as follows-

(A) Primary alcohols-

Those alcohols in which -OH group is attached to the 1° carbon atom is called primary alcohols.

For example-

           H

           |1°

      H-C-OH    (Methyl alcohol)

          |
          H

               H 

               |1°

      CH3-C-OH    (Ethyl alcohol)

               |
               H

(B) Secondary alcohols-

Those alcohols in which -OH group is attached to the 2° carbon atom is called secondary alcohols.

For example-

           CH3

           |2°

  CH3-C-OH    (Isopropyl alcohol)

           |
           H

  (C) Tertiary alcohols-

Those alcohols in which -OH group is attached to the 3° carbon atom is called tertiary alcohols.

For example-

           CH3

           |3°

  CH3-C-OH    (tert.butyl alcohol)

           |
           CH3

     

(2) Dihydric alcohols-

These are generally called as Glycol . The general formula of the Dihydric alcohols are (CH2)n(OH)2 , where n= 2,3,4 etc.
In this type of the alcohols 2--OH groups are attached to the two different carbon atoms.
For example-


  HO-CH2CH2-OH
 (Ethane-1,2-diol)


   CH3-CHOH-CH2-OH
  (Propane-1,2-diol)

(3) Trihydric alcohols-

In this type of the alcohols 3--OH groups are attached to the three different carbon atoms. In I.U.P.A.C. system these are known as alkanetriol.
For example-

     CH2-OH
     |
     CH-OH
     |
     CH2-OH
   
( Propane-1,2,3-triol)
Or Glycerol

Nomenclature of Haloalkanes

Nomenclature of Haloalkanes

The name of the haloalkanes are given by two different ways-

(1)Trivial or common system-

In this system haloalkanes are known as Alkyl halide.

       There nomenclature are performed by the adding halide word in the given alkyl group. In this system the name of the compound is written in the two different words.
   For example-
    CH3-Cl          (Methyl chloride)
CH3-CH2-Br     (ethyl bromide)                    

Prifixes of the different types of alkyl group-

(a) prefix- n

The means of prefix-n is normal. This is used in the straight chain of the Alkyl group.
 For example-

 CH3-CH2-CH2-Br                          (n-propyl bromide)


(b) prefix- iso

Prefix-iso is used for those Alkyl group in which methyl (--CH3) branch is present in the last of the chain.
For example-

CH3-CH-Br

         |

         CH3
  (Isopropyl bromide)


(c) prefix- neo


Prefix-neo is used for those Alkyl group in which two methyl (--CH3) group is attached in the last of the chain by a single carbon atom.
For example-

         CH3
         |
CH3-C-Br

         |

         CH3
  (neo butyl bromide)

(2) I.U.P.A.C. system-

In this system the monohalogen derivatives of the alkane is written as haloalkane.
For the naming of haloalkanes, fluoro, chloro, bromo or iodo prefix is writes before the longest carbon chain.
   The numbering is starts from the nearest halogen atom of the chain.
   The I.U.P.A.C. name of the haloalkanes is always writes in a single word.
  For example-

  CH3-CH-CH2-Br
           |
           CH3
   (1-bromo-2-methylpropane)



         CH3
         |
CH3-C-CH2-CH2-I
         |
         CH3
   (1-iodo-3,3-dimethylbutane)