All Students Notes

  Atomic structure: Discharge tube, discovery of cathode rays and properties of cathode rays Discharge tube   A glass tube containing two electrodes (cathode and anode) connected with high voltage battery and fitted with vacuum pump  is called a discharge tube.  Discovery of cathode rays   In the beginning, the electric current was passed through a gas enclosed in a discharged tube at an ordinary pressure and high voltage of 5000 volt, a glow was appeared. When pressure was reduced to 0.001 torr, and voltage was increased from 5000 to 10000 volts, a glow was disappeared. When pressure was further reduced, certain rays were produced from cathode and travel to anode. Such rays are called cathode rays.  These rays are called cathode rays because these rays are produced from cathode surface. Question: Why discharge tube does not allow the current to pass at ordinary pressure? Answer .  At ordinary pressure, electrons are not able to overcome the pressure applied on the surface of cathode b

 Water born diseases  Human waste is usually dumped on the ground or into the nearest stream. Human waste contains pathogenic organisms. These organisms are transmitted through food, water and direct contact. These microorganisms may cause typhoid fever,  dysentery and hepatitis. Chemical and bacterial contents in livestock waste can also pollute surface and ground water.  Cholera   Cholera is an intestinal disease. It is caused by bacteria such as vibrio Cholera., E. Coli etc.which may be present in water contaminated with human waste. It causes purging and vomiting. Dysentery   Dysentery is also an intestinal disease. It is caused by parasite,  Entamoeba. The infection is transmitted by faecel contamination of water or food by encysted organisms. Patients have mild to severe abdominal cramps, diarrhea, chocolate colourd stool with mucous and sometimes with blood. Jaundice   This disease proceeds from obstruction of liver. Excess of bile from the liver enters in the blood and causes y

  Water Pollution   Water is a very good solvent as it dissolves many substances. This property is due to polarity of water molecules and its ability to form hydrogen bonds with other substances. For instance, a water from rain 🌧 and snow ❄️ flow over rocks and through the soil, it dissolves minerals. A fresh water that we drunk or iluse in daily life is not pure water, rather it is a dilute solution containing a number of minerals. When concentration of these minerals becomes sufficient high, the water becomes unfit for human use.  Many human activities also contribute to the pollution of surface and ground water. Human activities include household waste, agriculture waste,  livestock wastes, pesticides, oil leaks, detergents, septic tanks, petroleum, natural gas production may result in water pollution.  Household wastes Household wastewater (also known as domestic wastewater or municipal wastewater) water that contain soaps, detergents, livestock wastes, pains and oil food and vege

Hardness of water ant its removal   The ability of water to dissolve a wide variety of substances is due to its two important properties: Its polarity and ability to form hydrogen bonds. Due to its polar nature it can also dissolve such cations which causes its hardness. Its hardness results in wastes of soap, spoiling of fabrics, blockage of pipes, boiler, radiator and great damage. There are various methods which are used its removal. Hard water   Water that contain high content of minerals such as Ca2+ and Mg2+ is called hot water.  OR The water that gives little lather are forms scum with soap is called hard water. Soft water   Water that contain little content of mineral is called hot water. OR  The water that gives more lather and forms little  scum with soap is called hard water

  Environmental Chemistry II: Water Properties of Water   Occurrence   Water is one of the most important substances on the earth 🌎.  It is present in enormous quantity on earth. It has been estimated that the total amount of water on earth is about 1.33 billion cubic meters which approximately covers 71% of the earth's crust.  Despite of an  enormous amount of water on earth surface, fresh water available for drinking is only 3% of the total. This small amount of water is not evenly distributed on earth. Some areas are rich in fresh water while certain areas have little or no fresh water. Of this fresh water, 69% resides in glaciers, 30% underground 🚇 water and less than 1%is present in lakes, rivers, and swamps. Sea water that is almost 97% of total water, contains large amount of dissolved salts. The sodium chloride is the most abundant salt in sea water 🌊. It is present upto 3.4% in it. Importance of water Earth 🌎 is the only planet in the solar system that contains water. 

  Question: Define pollutants. Describe various pollutants that cause pollution. Answer. Pollutant Any substance that is present in air, water or soil and has an adverse effect on some other part of              environment is called pollutants. Pollutants have harmful effect on both health and quality of health of human being. Some of important air       pollutants are given as follows. i.          Sulphur oxides (SOx) ii.        Carbon monoxides iii.      Nitrogen oxides (NOx) iv.      Methane v.        Chlorofluorocarbons (CFCs) vi.       Lead compounds vii.     Ozone Sulphur oxides (SOx) Sulphur oxides are produced when fossil fuels such as coal and petroleum are burnt. Sulphur dioxide (SO 2 ) Sulphur dioxide (SO 2 ) easily reaches the lung and disturb respiratory system. Patients with asthma are at high risk in presence of SO 2 . It reduces lung function, increases the respiratory disease and causes irritation of eyes, nose and throat. Sulphur trioxide (SO 3 ) Sulphur trioxide is

 Environmental Chemistry ⚗️  Atmosphere: The envelope of gases and water vapors surrounding our earth 🌎 is called atmosphere. Composition of Atmosphere: Air is a mixture of gases which are given below. Nitrogen     = 78% Oxygen        = 21%  Other gases               % by volume   Argon                            0.93 Carbon dioxide            0.038 Neon                              0.0018 Helium                          0.000052 Methane                       0.00015  Krypton                       0.00011 Hydrogen                     0.00005 Question: Why water vapors have not been included in composition of Atmosphere? Answer. Besides gases, there are varying amounts of water vapors in the air.  For example, there is little water in the air over the desert 🏜. Whereas in the tropical rain forest area  the air may contain upto 4% water vapors. This means  that amount of vapors in air varies from place to place and time to time. Therefore content of water vapors has not been included i

  Vitamins: Definition, Examples, Types, Sources and Uses Definition: The organic compounds which are required by our bodies to prevent specific diseases but cannot be produced by our bodies are called vitamins. These compounds must be present in our diet in addition to proteins, fats, carbohydrates and minerals. Examples, vitamin A, vitamin B Complex, vitamin C, vitaminD Types of vitamins  There are two types of vitamins. Fat soluble vitamins  Water insoluble vitamins  Fat soluble vitamins  A vitamin that is soluble in fats is called fat soluble vitamin. For example, vitamins A, D,E and K. Taking excessive amount of fat soluble vitamins can be harmful.  For example, excessive amount of vitamin A can cause irritability, dryness  of skin and pressure inside the head. Similarly, Taking excessive amount of vitamins D can cause pain in bones, hard deposits in joints and kidneys. And weight loss. Water insoluble vitamins A vitamin that dissolve in water is called water soluble vitamin. For

 Nucleic acids: Definition, Structure, Types, DNA and RNA Definition: The nitrogenous compounds which were first obtained from the pus of infected wound are known as nucleic acids.  Components   Nucleic acids are long chain molecules made up of nucleotide. Each nucleotide consists of three components.   I. Nitrogenous base   ii. A pentose sugar or five carbon sugar    iii. Phosphate group  Kinds of Nucleic Acids   There are two kinds of nucleic acids, Deoxyribosenucleic acid (DNA) and ribonucleic acid (RNA) Deoxyribose Nucleic acids (DNA)   DNA exists in the form of two strands.  These two strands are twisted around each other in spiral form also called double helix.  Each strand is made up of a deoxyribose sugar, phosphate uni and a nitrogen base.  These strands are held together by hydrogen bonds. The order of base pairs in a strand forms a code that stores genetic information which is used to produce proteins.  The main function of DNA is to store the genetic information and to pass

 Definition: A lipidmay be defined as Any component of plant 🪴  or animal  (🐃, 🦌, 🐐) that is soluble in water,  but insoluble in solvents of low polarity such as ether, hexane,benzene  and carbon tetrasaccharide is known as lipid. For example:  a. Fats and oils b. Cholesterol 🛢  c. Sex harmones  d. Components of cell membrane called phospholipids  e. Some vitamins (A, D, E and K) Fats and oils Fats and oils are known as simple lipids. They are esters of fatty acids (long chain carboxylic acid) with a trihydroxy alcohol, glycerol. Therefore, they are also called glyceryl esters or glycerides. They are building blocks of lipids. For example, stearic acid, C17H35COOH is an acid that occurs in animal fats. A lipid is called fat if it is solid at room temperature 🌡.  A lipid is called oil if it is liquid at room temperature 🌡.  Sources   Animals, 🐃 🦌, 🐐  plants 🪴,  and marine 🐟 🐠 🐋 organism such as salmon and whale 🐋 are rich source of lipids. Cod liver oil is obtained from s

  Definition:   Proteins are complex nitrogenous compounds that produce amino acids on complete hydrolysis. Functions: Proteins have many functions in the human body. For example, 1. They transport and store Oxygen and nutrients. 2. The act as catalyst for the thousands of reaction that take place in the body to make life possible. 3. They regulate many important systems in our bodies. Amino acid as building block Building blocks of all proteins are are the proteins, therefore on hydrolysis, all proteins produce amino acids on hydrolysis. An amino acid has two functional groups.  There are twenty different amino acids which are involved in proteins synthesis. Out of twenty amino acids, our body can synthesis only ten amino acids. These amino acids are called essential amino acids. The remaining amino acids which our body cannot  synthesis is called essential amino acids. An amino acid has two functional groups: amino group and carboxylic group. Molecules of amino acids are joined toget

  Carbohydrates are macromolecules defined  as Polyhydroxy aldehydes or ketones. They have general formula Cn(H2O)n. Synthesis  Plants synthesize carbohydrates through photosynthesis. In this  process plants convert carbon dioxide and wat er into glucose in the presence of sunl i ght and green pigment chlorophyll. Classification: Carbohydrates are classified as  1. Monosaccharaides   2. Oligosaccharides  3. Polysaccharides  1. Monosaccharide The carbohydrates which cannot be further hydrolyzed. These are also called simple sugars. They consist of 3 to 9 carbon atoms. They are further classified as trioses, tetroses, pentoses, hexoses, and so on depending on number of carbon atoms in their molecules, The important monosaccharaides are hexoses like glucose and fructose, etc.  Properties   • Monosaccharaides are white crystalline solids.  • They are sweet in taste and soluble in water  • They cannot be hydrolyzed.  • They are reducing in nature, therefore, these are called reducing sugars

Definition  An atom are group of atoms that give a family of organic compound it characteristics chemical and physical properties is called functional group.  Function group is based for the classification of organic compound it has made the study of million of organic compound very easier. For example,  CH3--OH      CH3-Cl    CH3CH2Br  Function groups containing carbon hydrogen and halogen:Haloalkane  The organic compound in which one hydrogen atom of an alkane is substituted by one halogen atom is called hello alkane. R-X is the general formula of haloalkane.  CH3-Cl    CH3-CH2-Br     CH3-CH2-Cl Function group containing carbon hydrogen and oxygen: Alcohol Organic compounds in which one hydrogen atom of alkane is substituted with hydroxyl group (OH)  is called alcohol. CH3-OH        CH3-CH2-OH          CH3-CH2-OH They have general formula of R-OH. Phenol: Phenols are organic compounds in which hydroxyl group is attached to a benzene ring. Phenol was the first compound used in an oper

 Classification of organic compounds, alkane and alkyl radical Classification of organic compounds There are millions of organic compounds, so it in not possible to study each compound individually. To make their study easier, they are classified into various groups and sub groups. This classification is based on carbon skeleton.  These organic compounds are broadly classified into two main groups. I. Open chain compounds or acyclic compounds  2. Closed chain or cyclic compounds  I. Open chain compounds or acyclic compounds  Open chain ⛓️ compounds contain an open chain of carbon atoms. Open chain compounds are also known as alicyclic compounds. For example,  CH3--CH2--CH3      CH3--CH2--CH2--CH3     CH3--CH2--CH2--CH2--CH3      Propane                    Butane                              pentane Open chain compounds are further classified into two sub groups  a. straight chain organic compounds  b. Branched chain organic compounds  a. straight chain organic compounds  The open chain

  Organic Chemistry:Sources and uses of organic Compounds The major commercial sources of alkane are called natural gas Petroleum and living organisms. Coal  Coal is a source of many organic compounds. When coal is heated in the absence of air and high temperature it is converted into coal gas, coal torr and coke. This process is called destructive distillation.   Coal gas contains methane, hydrogen and carbon monoxide gases . it is mainly used as a fuel in industry. Coke is a source of many organic compound such as benzene and its derivatives.  These compound can be separated by fraction distillation there are very useful substances in synthetic organic chemistry.  These are used in synthesis of plastic  dyes  paints, drug, varnishs, The residue left behind is called pitch is used to metal road and roofs.   coal is also used as a solid fuel. Natural gas Natural gas is a mixture of low boiling hydrocarbons. Major portion of natural gas is methane gas. It also contains a small amount of

 Structural formula and condensed Structural formula of organic compounds  Structural formula A formula that describes arrangement of atoms in a molecule is called as Structural formula. For example,  Condensed Structural formula: A formula that uses established abbreviations for various groups of carbon chain.  For example,   Name       Molecular formula        Condensed formula  Bttane     C4H10                              CH3-CH2-CH2-CH3  Pentane   C5H12                          CH3-CH2-CH2-CH2-CH3 Hexane    C6H14                       CH3-CH2-CH2-CH2-CH2-CH3 Heptane   C7H16                    CH3-CH2-CH2-CH2-CH2-CH2-CH3 Octane      C8H18                  CH3-CH2-CH2-CH2-CH2-CH2-CH2-CH3 None         C9H20                CH3-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH3 Decade    C10H22            CH3-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH3 Saturated and unsaturated hydrocarbons Hydrocarbons whose carbon- carbon bonds are all single bonds are called saturated Hydrocarbons.  Saturated Hydrocarbons are

  Organic compounds and their general characteristics  Organic Compounds : The hydrocarbons and their derivatives are called Organic compounds.  Question: Why is there chemical diversity and magnitude of organic compounds? Answer. Chemical diversity and magnitude of organic compounds arise due to following properties of organiccompounds. 1. Catenatination 2. Isomerism  3. Formation of multiple bonds 1. Catenatination  A carbon atom has ability to make bond with other carbon atoms. This self linking property of carbon is called catenatination. Due to this property, carbon forms almost infinite ♾️ number of organic compounds of various size, shapes and structures.   2. Isomerism The compounds that have same molecular formula but different arrangement of atoms in their molecules are called  isomers and this phenomenon is called iisomerism.  For example, molecular formula of n-butane and iso-butane is same but arrangement of atoms are different.  So both are isomers of each other. CH3-CH2

 Salts, method of making salts and uses Salt When replaceable hydrogen atoms of an acid is partially or completely replaced by metal atoms, the resulting compound is called salt. For example,      HCl     +          Na   ------->    NaCl      +   H2      Acid             metal              salt        Salts are ionic compound. The first part of the name is metal ion and second part of the name is of negative part of the acid.    Some common examples acids and their salts           Acid                               salts           HCl                          NaCl, KCl, CaCl2,  (Hydrochloric acid) ---‐------------------------------------------------------------------------          HNO3                      NaNO3, KNO3, Ca(NO3)2     (Nitric acid)      ---‐------------------------------------------------------------------------         H2SO4                     Na2SO4, K2SO4, CaSO4  (Sulphuric acid )  ---‐------------------------------------------------------------------------ H3PO

PH of solution and ph scale and measurement of PH Ph Scale:  A number scale ranging from 0 to 14  that is used to describe the concentration of H+ ions in a solution is called pH scale. Measurement of pH Scientists usually use three methods to measure the pH of solution. These are:     1. Measurement of pH using paper or universal indicator.     2. Measurement of pH using Litmus paper     3. Measurement of pH using   Acid-base indicator  1. Measurement of pH using paper or universal indicator . PH paper or universal indicator paper is used to measure pH of a solution. For this purpose pH paper is dipped in the solution. The color that develops on the pH paper is compared to color of known pH on the chart. On chart, each color has a specific pH. 2. Measurement of pH using Litmus paper One of the most commonly used methods in chemistry laboratory is the use of litmus paper. It is used to give a general indication of solution weather it is an acidic or basic. Litmus paper may be red or bl

 Self ionization of water or auto-ionization of Water The in which two water molecules produce ions is called as self ionization or auto-ionization of water. This reaction  can be written as follows.          H2O   ----------> H+,      +      OH-  Explanation: When molecules colloid with each other with enough energies, a protons is transferred from one molecule to an other molecule. A water molecule that donates or loses proton becomes negatively charged and other water molecule which gains or accepts proton becomes positively charged hydronium ion H3O+. Equilibrium constant expression for self ionization of water can be written as follows.            K c  =    [H+][OH-] / [H2O] Since, H2O is a weak electrolyte, so concentration of [H2O] remains constant.           K c   [H2O] = [H+][OH-]           K w  =  [H+][OH-]    •••••••••••    1      Where K w  = [H + ][OH - ]  is called ionization constant of water. It is also called ionic product of water. For example,  At 25oc, experi