Knowledge of Science

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 (ऐ

ईथर के निर्माण की सामान्य विधियाँ (General methods of preparation of Ethers ) ईथर का निर्माण निम्न विधियों द्वारा किया जा सकता है - (1) हैलोऐल्केन द्वारा -  हैलोएल्केन (एल्किल हैलाइड) से ईथर बनाने के लिए निम्नलिखित विधियां प्रयोग में लाई जाती है- (a) विलियमसन संश्लेषण द्वारा - यह ईथर निर्माण की एक श्रेष्ठ विधि है| इस विधि में एल्किल हैलाइड की क्रिया उपयुक्त सोडियम (या पोटैशियम)अल्कॉक्साइड के साथ कराई जाती है| R-ONa + R-X ------> R-O-R + NaX  CH3-ONa + CH3Br  ------> CH3-O-CH3 + NaBr   C6H5-ONa + CH3Br  ------> C6H5-O-CH3 + NaBr  (b) हैलोएल्केन को शुष्क सिल्वर ऑक्साइड के साथ गर्म करके-  हैलोएल्केन को शुष्क सिल्वर ऑक्साइड के साथ गर्म करके भी इधर का निर्माण किया जा सकता है जैसे- 2CH3CH2Br + Ag2O -------> CH3-O-CH3 + 2AgBr  (2) ऐल्कोहलो से - (a) ऐल्कोहलो के निर्जलन से - जब अल्कोहल के आधिक्य को 413 K पर सांद्र H2SO4 के साथ गर्म करते हैं तो एक अणु ईथर व एक अणु जल बनता है |                    conc.H2SO4 ROH + HOR ----------------> ROR + H2O  CH3CH2OH + HOCH2CH3 ----------->

एल्कोहॉलों के रासायनिक गुण (Chemical properties of alcohols )- सामान्यतः एल्कोहॉलों  की क्रियाओं को निम्नलिखित तीन  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 (C) एल्किल तथा हाइड्रॉक्सिल  दोनों समूहों की निहित अभिक्रियाये  (A) अभिक्रियायें  जिनमें O-H आबंध का विदलन होता है (1) ऐल्कोहॉल का अम्लीय लक्षण - ऐल्कोहॉल दुर्बल अम्ल की तरह व्यवहार दर्शाते हैं और अल्प मात्रा में निम्न प्रकार आयनित होते हैं - R-O-H      <=>        R-O´  +  H+ CH3-O-H   <=> CH3-O´  +  H+  ऐल्कोहॉल की अम्लीय प्रकृति O-H बंध  की ध्रुवीयता  के कारण है| अधिक विद्युत ऋणात्मक होने के कारण O  परमाणु O-H  बंध के  साझा इलेक्ट्रॉन युग्म को अपनी ओर खींचता है| इस कारण साझा इलेक्ट्रॉन युग्म O  परमाणु की ओर  विस्थापित हो जाता है तथा O-H बंध  दुर्बल हो जाता है| परिणाम स्वरूप अणु  से प्रोटोन(H+) का निकलना सरल हो जाता है| इस कारण ऐल्कोहॉल  दुर्बल अम्ल की भांति व्यवहार करते हैं| इनकी अम्लीय प्रबलता जल की तुलना में कम होती है

                                Human nervous system Human nervous system is the most complex. It is divided into two main parts:- (1) Central nervous system (2) Peripheral nervous system (1) Central nervous system- It is Hollow and lies on the mid dorsal part along the main axis of the body it is covered externally by part of axial skeleton. The CNS, in turn, consists of two parts:- (A) Brain or encephalon situated in the head (B) spinal cord or myelon located in the neck and trunk. (A) Brain (Encephalon)- The brain is the widest and the the uppermost part of the central nervous system. It is the highest coordinating centre in the body. Brain is situated in the cranial cavity of the skull in the head region of the body. The bones of cranium or brainbox protect this delicate organ from mechanical injury. Inside the box, the brain is contained in a fluid- filled baloon which provides further shock absorption. The study of brain in all aspects is calle

Nutrition in human beings- Human beings are heterotrophic omnivorous organisms. They obtain their food from plants, animals and their products by holozoic mode of nutrition. The essential components of human diet are  water, carbohydrates, fats, proteins, minerals and vitamins. Human Digestive system- The human digestive system consists of an alimentary canal and many digestive glands. So human digestive system is divided into two main parts the first one is the alimentary canal and the other one is different digestive glands associated with alimentary canal. (1) Alimentary canal (2) Digestive glands associated with alimentary canal (1) Alimentary canal- The alimentary canal is a long tube with muscular walls, glandular epithelial lining and varying diameter. It extends from the mouth to the anal opening (anus). When uncoiled, the alimentary canal measures nearly 9 metre long tube in which the ducts of several digestive glands open to secrete their respective digestiv

Carbohydrates- Importance- The carbohydrates are often termed as sugars are the 'staff of life' for most organisms. On the basis of mass, they are the most abundant class of biomolecules in nature. Carbohydrates are also known as saccharides (sakcharon = Sugars or sweetness) since many of those of relatively small molecular weight have a sweet taste, although this is not true of those with large molecules. They are widely distributed molecules (moles = mass) in both plant and animal tissues. They are indispensable for living organisms, serving as a skeletal structures in plants and also in insects and crustaceans. They also occur as food reserves in the storage organs of plants and in the liver and muscles of animals. In addition, they are an important source of energy required for the various metabolic activities of the living organisms; the energy being derived as a result of their oxidation. They also serve to lubricate skeletal joints, to provide adhesion  between cell

Reproductive system of human beings - Human beings are unisexual and the human reproduction is highly evolved. There is a distinct sexual dimorphism. Thus, the structures associated with reproduction are different in males and females. The structures associated with male reproduction constitutes the male reproductive system. similarly, The structures associated with female reproduction constituted the female reproductive system. The reproductive systems of males and females consists of many organs which are distinguishable into primary and secondary sex organs. Primary sex organs- The primary sex organs are gonads, which produce gametes and sacrete sex hormones. The gonads of the male are called testes which produce male gametes- sperms and the male hormone- testosterone . The gonads of the female are ovaries which produce female gamete- ova and female hormones -estrogen and progesterone. Secondary sex organs- The secondary sex organs include the genital ducts and glands which

Blood circulatory system    (Blood vascular system ) Blood circulatory system is regarded as a kind of vascular system and therefore, it is called blood vascular system. A vascular system is that which has tubes full of fluid to be transported from one place to another.  The blood vascular system comprises of heart, the organ which pumps and receives the blood, and blood vessels, which are tubes through which the blood flows.      Blood vessels- The blood vessels are elastic muscular tubes which carry blood. There are three kinds of blood vessels in human body.     They are of three types-(1)Arteries  (2)veins and  (3)capillaries. (1)Arteries- Arteries are the thick walled blood vessels which carry blood away from the heart for distribution to the body. The walls of arteries particularly those near the heart are thick that enables them to dilate but not rupture when the heart contracts and forces blood into them. Thus the blood passing through narrow lume

      Excretion in human beings Excretory system- Excretory system in human beings (also known as urinary system) consists of a pair of kidneys, a pair of ureters ,a urinary bladder and a urethra . The two kidneys are located towards the back of the lower part of the abdominal cavity, one on either side of the backbone. Left kidney is slightly larger and placed a little higher than the right kidney. The blood from aorta enters into kidneys via the renal arteries and returns to the posterior Vena cava via renal veins. Urine formed in the kidneys passes by a pair of ureters to the bladder where it is stored until it is released via the urethra. Structure and function of kidneys- There are two kidneys in humans each kidney is purplish- brown, slightly flattened and shaped somewhat like rajma Bean. It is about 12 centimetre long, about 6 CM thick and wait about 150 grams. Internally a kidney is made of numerous microscopic excretory units called nephrons. Single kidney contai

      Refraction of light The change in direction of light when it passes from one medium to another obliquely is called refraction of light.           In other words the bending of light when it goes from one medium to another obliquely is called refraction of light.           The  Refraction of light  takes place when light rays enter from air into glass , or from glass into air. The refraction of light takes place when light enters from air into water, or from water into air. And the refraction of light also takes place when light enters from water into glass or from glass into water.        The optical instruments like camera, microscope and telescope work on the the refraction of light through glass lenses.     The refraction (or bending ) of light takes place at the boundary between the two media. Causes of refraction- The refraction of light  is due to the change in the speed of light on going from one medium to another. Thus, when light goes from one medium to

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 f

                     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

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) gro

      Haloalkanes and Haloarenes Haloalkanes-  The word Haloalkane is made up by the two words, -          Halo = halogen          Alkane= Aliphatic hydrocarbon (containing single bond only) So, Haloalkanes are those compounds which is formed when a hydrogen atom replaced by any halogen atom from the alkanes.                - H    R-H  -------------->      R-X                 +X Where ,   R  =  Alkyl group               X  = Halogen ( F,Cl, Br, I) For example-                                  - H          CH3-H  --------------> CH3-Cl                            +Cl Haloarenes-  The word Haloarene is made up by the two words, -          Halo = halogen    Arene= Aromatic hydrocarbon So, Haloarenes are those compounds which is formed when a hydrogen atom replaced by any halogen atom from the arenes.                - H    Ar-H  -------------->      Ar-X                 +X Where ,  Ar  =  Aromatic hydrocarbon               X  = Halogen ( F,Cl, Br,