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                                                        Important Questions Q In the hydrogen bonded structure of HF which is stronger bond. The shorter covalent or the longer Hydrogen bond between the different molecules. Ans: Hydrogen bond of HF is shown below                    Shorter covalent bond H___F is stronger than the longer Hydrogen bond F.....,H longer bond. The Covalent bond is twenty times Stronger than the hydrogen. Q In a very cold water fish in garden ponds owe their lives to H-bonding. Ans: When the temperature surroundings falls up to 4 C Degree water on the surface is freezes. During the process of freezing water molecule arrange in hexagonal fashion due to the hydrogen bonding and empty spaces are created. As a result volume of ice increases and density decreases. This layer of ice insulates the water under it for further heat loss which stays at 4 C degree as liquid. Hence fish can survive at this temperature and all this is due to the hydrogen bonding. Q

                                                     Important Questions Q What are the faulty assumption of the K M T ? Ans: According to van der Waal (1873) two postulates of Kinetic Molecular . The gases are faulty which under as                       There is no force of attraction among molecules of a gas                        The actual volume of gas molecules is negligible as compared to the volume of vessel. Q Define the pressure Give Its unis. Ans: The force on a unit area is called pressure             The SI unit for the pressure is Nm-2 or the Paascal. Q Define the partial pressure and how it can be calculated? Ans: The individual pressure exerted by each gas in mixture of non reacting gasses is called Partial pressure.               Let us suppose that we have a mixture of Gas A and B This mixture is enclosed in a container having volume (V). The total pressure is one atm. The number of moles of the gas A and B are nA and nB respectively. If they are maintain

                                                            Important Question Q  How the desiccators are used for drying of crystals ? Ans: A safe and reliable method of drying crystals is trough vaccum desiccators. In this process the crystal are spread over a watch glass and kept in the vaccum desiccators for several hours. Drying Agents: The drying agents used in desiccators are CaCl2 sillica gel or P2O5 Q Why there is needed to crystallize the crude product ? Ans: When a chemical compound is prepared it is not pure rather a crude product. It is therefore purified by process of crystallization using a proper solvent. Q Define the sublimation. Why solid iodine during sublimation is directly converted in to vapours ? Ans: t is the process in which a solid on heating vapourizes directly with out passing trough the liquid state these vapours can be condensed to form solid again. This technique is frequently used to purify the volatile solids. Examples of the volatile solids a

                                           Important Questions Q Law of conservation of mass has to be obeyed during the stoichiometric calculations. Ans: Stoichiometric calculation are base upon the balanced chemical equation so the number of moles of the reactant in equal to the number of moles of product. As the numbers of moles of atoms are equal hence their masses should be equal in reactant and product which is according to the law conservation of masses other wise the calculation are not possible. Q Many Chemical Reactions taking place in our surrounding involve limiting reactant. Ans: Many chemical reactions taking place in our surrounding involves the limiting reactant. If it is not so the reactions will go countinously and would never stop. But due to this limiting reactant the reaction stops after complete consumption of limiting reactant. For Example, when the wood burns it reacts with the oxygen of air which is in excess. But after complete consumption of the wood

                                                     Environmental Chemistry Q What is smog ? Different between the oxidizing and reducing smog. Ans: The word is smog combination of two words : Smoke and fog  The smog containing the high contests of SO3 which is reducing in nature is called the reducing smog while the smog containing the high concentration of oxidizing agents like Ozone is called the Oxidizing Smog. Q Give the conditions for smog formation. Ans: Following are the required conditions for the formation of smog Sufficient amount of NO, Hydrocarbons and volatile org compound emitted by vehicles. Presence of the sunlight to carry out the reactions at rapid rate. Movement of air mass must be little so that reactions are not disturbed. Q Define the environment. Name components of environment. Ans: Environment can be defined as the combination of biotic and abiotic components present at same place interacting with each other. components of environment are

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                                                    Important Questions  Q1 Define the manure ? Ans Manure can be defined as the organic material used to fertilize the land usually consisting of the faeces and urine of domestic animals. Q2 What are the fertilizers ? Why they are needed ? Ans Fertilizers are the chemical substances added to the soil make up the deficiency of essential elements like N,K,P required for the proper growth of plants. Fertilizers are needed to enhance natural fertility of land or soil & replenish the chemical elements taken up previous plants. Q3 Different between the micro and macro nutrients ? Ans Micro nutrients: These are nutrients which are required in very small quantities for the proper growth of plants e.g B,Cu,Mn,Zn Mo & Cl. They are generally required in the range of 6 to 200 grams per acre. Macro nutrients : These are nutrients which are required in very large quantities for the proper growth of plants e.g N,P,K,Ca,Mg,S,C,H &

                                                             Important Questions Q1 Define carboxylic acids. give their Classification. Ans The organic compounds containing the carboxyl group as a functionality are called carboxylic acid. the group is itself combination of carbonyl group (>C=O) and hydroxyl group (OH) Carboxylic acid may be aliphatic or aromatic depending upon whether -COOH group is attached with an alkyl or aryl group.                Aliphatic Carboxylic acid R-COOH                 CH3COOH  Acetic acid              Aromatic Carboxylic acid     Ar-COOH             C6H5COOH Benzoic acid Q2 What are fatty acids ? Give their examples  Ans The aliphatic monocarboxylic acids are called the fatty acids because they higher members of this series such as Palmitic acid ( C15H31COCOH)Stearic acid are obtained by the hydrolysis of fats and oils. Q3 Discuss the reactivity of Carboxyl group. Also write down the reactions of carboxylic acids. Ans : The caboxylic