Science Question paper 2022 ,term 2

latest question papers-2022(term 2) class -10th sub- Science Set 1

   

SET 3

Assignment class 10th : Chemistry chepter 1. Chemistry

MORRISON & BOYD ORGANIC CHEMISTRY PDF

Morrison & Boyd Organic Chemistry Topics organic chemistry, analyzed. Features Collection opensource A popular introduction to organic chemistry which stresses the importance of molecular structure in understanding the properties and principles of organic chemistry. Addeddate 2016-10-13 20:15:24 Identifier MorrisonBoydOrganicChemistry Identifier-ark ark:/13960/t10p60j7s Ocr ABBYY FineReader 11.0 Ppi 600 Scanner Internet Archive HTML5 Uploader 1.6.3

Base-catalysed hydrolysis of esters by a Kumar

Base-catalysed hydrolysis of esters is irreversible: You can’t make esters from carboxylic acids and alcohols under basic conditions because the base deprotonates the carboxylic acid. However, you can reverse that reaction and hydrolyse an ester to a carboxylic acid (more accurately, a carboxylate salt) and an alcohol. This time the ester is, of course, not protonated first as it would be in acid, but the unprotonated ester is a good enough electrophile because OH–, and not water, is the nucleophile. The tetrahedral intermediate can collapse either way, giving back ester, or going forward to acid plus alcohol Without an acid catalyst, the alcohol cannot react with the carboxylic acid; in fact, the backward reaction is doubly impossible because basic conditions straight away deprotonate the acid to make a carboxylate salt (which, incidentally, consumes the base, making at least one equivalent of base necessary in the reaction).

12th Chemistry practical 2022

Polymers: class12th pdf

The use of polymers in the manufacture of plastic buckets, cups and saucers, children’s toys, packaging bags, synthetic clothing materials, automobile tires, gears and seals, electrical insulating materials, and machine parts has completely revolutionized the daily life as well as the industrial scenario. Indeed, polymers are the backbone of four major industries viz. plastics, elastomers, fibers, and paints, and varnishes. The word ‘polymer’ is coined from two Greek words: poly means many and means unit or part. The term polymer is defined as very large molecules having high molecular mass. These are also referred to as macromolecules, which are formed by the joining repeating structural units on a large scale. The repeating structural units are derived from some simple and reactive molecules known as monomers and are linked to each other by covalent bonds. The process of formation of polymers from respective monomers is called polymerization. There are several ways of classification polymers based on some special considerations. One of the common classifications of polymers is based on the source from which the polymer is derived. Under this type of classification, there are three subcategories. Natural polymers These polymers are found in plants and animals. Examples are proteins, cellulose, starch, some resins and rubber. What are polymers? There are two broad types of polymerization reactions, i.e., the addition of chain-growth polymerization and condensation or step-growth polymerization. In this type of polymerization, the molecules of the same monomer or different monomers add together on a large scale to form a polymer. The monomers used are unsaturated compounds, e.g., alkenes, alkadienes, and their derivatives. This mode of polymerization leads to an increase in chain length and chain-growth can take place through the formation of either free radicals or ionic species. However, the free radical governed addition or chain-growth polymerization is the most common mode. (a) Polythene Polythenes are linear or slightly branched long-chain molecules. These are capable of repeatedly softening on heating and hardening on cooling and are thus thermoplastic polymers. There are two types of polythene as given below: (i) Low-density polythene: It is obtained by the polymerization of ethene under high pressure of 1000 to 2000 atmospheres at a temperature of 350 K to 570 K in the presence of traces of dioxygen or a peroxide initiator (catalyst). The low-density polythene (LDP) is obtained through the free radical addition and H-atom obstruction. It has a highly branched structure. These polymers have a straight-chain structure with some branches as shown below. Author NCERT Language English No. of Pages 14 PDF Size 1483 KB Category Chemistry Source/Credits ncert.nic.in Download Textbook NCERT Solutions Class 12 Chemistry Chapter 15 Polymers Q2: What are natural and synthetic polymers? Give two examples of each type. Solution: Polymers naturally found are known as Natural Polymers. Natural polymers are formed from animals and plants. Diverse natural polymer examples are protein, starch, cellulose, etc. Polymers that are human-made are known as Synthetic Polymers. Various examples of synthetic polymer are synthetic rubbers (Buna-5), synthetic fibers (nylon 6, 6), and plastic (polythene). Q3: Distinguish between the terms homopolymer and copolymer and give an example of each. Solution: HOMO-POLYMER CO-POLYMER The polymerisation of a single monomer results in the creation of polymers called homo-polymers. Or put it another way, the repeating units of homo-polymers are formed from one monomer. For example, the homopolymer of ethane is polythene. Co-polymers are polymers whose repeat units are obtained from two-type monomers. Examples: Co-polymer of styrene and 1, 3 – butadiene is Buna – S. Q4: How do you explain the functionality of a monomer? Solution: The function of a monomer may be defined as the total number of binding sites, which are in this particular monomer. For example, adipic acid and 1, 3-butadiene is two and that of propene and ethene is one Q7: Determine the groups where the polymers are graded according to molecular forces? Solution: Polymers are classified into groups given below based on the intermolecular magnitude of forces present in polymers: (a) Fibres (b) Elastomers (c) Thermosetting polymers (d) Thermoplastic polymers https://drive.google.com/file/d/1gCNjZ-coJVGYeE7lu0h7y0jDgNOaRUMY/view?usp=drivesdk

Biology notes class 11th.pdf

CBSE Class 12 Biology Notes: Chapter wise CBSE Class 12 Biology Notes are provided to help student prepare well for the exams. Through CBSE Notes for Class 12 Biology students can make the most out of their study time. Biology Notes for Class 12 include well-researched information about all the chapter topics and students will be able to understand each topic clearly. With these CBSE Notes for Class 12 Biology, students will further be able to revise all the important topics quickly and be stress-free especially before the board examinations. The CBSE Class 12 Biology Notes have been prepared by subject experts and covers each chapter in detail. Additionally, these CBSE Class 12 Biology Notes involve both the questions and answers which are most expected to appear in Class 12 board examination. Students will also find neat and labelled diagrams to all the questions that are mainly based on the NCERT textbook. Students can refer these CBSE Class 12 Biology Notes both for their home assignments and exam preparation. CBSE Class 12 Biology Notes for All Chapters Biology is the most interesting and scoring subject which is further full of amazing facts and exclusive discoveries. Biology is also one of the important subjects in the science stream and obtaining good marks in this subject could help students land placement in good medical institutions and others. As it is important to score a good percentage in the exams, it is not enough to study from the Class 12 textbook. Students need some effective study materials and study tools such as CBSE Notes for Class 12 Biology. So, to help them, we have compiled the CBSE Class 12 Biology Notes for all the chapter. Students can also access the CBSE Notes for Class 6 to 12 compiled at one place. Check the links given below to access chapter-wise Class 12 Biology Notes of CBSE board.

Assignment class 12th hemistry chepter 2

you must explain in detail not tick Correct option. SECTION A Section B (theoretical) 1.State Henry’s law and mention some important applications. 2. Define :- a. isotonic solution b. plasmolysis c. reverse osmosis d. abnormal molar mass e. dessication constant f. molality g. solibity h. Mole fraction