Sách giáo khoa Hóa Tiếng Anh 12

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Sách Hóa Học Lớp 10 (Song Ngữ Việt Anh) 
 Nhà xuất bản Giáo dục Việt Nam đã có công văn số: 1114NXBGDVN ngày 18 tháng 07 năm 2014 Vv phát hành bộ sách giáo khoa Toán Lý Hóa song ngữ Việt – Anh năm học 2014 – 2015 Chapter1: ESTERS-LIPIDS  What are esters, lipids?  Properties and applicatios of esters lipids in human life Esters make the aroma of flower Lesson 1: ESTERS To know the definition, properties, and some applications of esters I – DEFINITON, NOMENCLATURE Consider the reactions: Ethyl acetate + CH3COOH + H2 O isoamyl acetate Ethyl acetate, isoamyl acetate belong to esters Thus, an ester is obtained by replacing the OH group in the carboxylic group of a carboxylic acid with an OR group Monofunctional esters is RCOOR’, where R is a hydrocarbon moiety or H; R’ is a hydrocarbon moiety A saturated acylic monofunctional esters is formed from a saturated acylic, monofunctional acid and saturated monofunctional alcohol It has molecular formula CnH2nO2 ( where n≥2) The name of an ester includes the name of the alkyl R’ and the name of the acid (suffix “ate”) For example: CH3COOC2H5: ethyl acetate, CH2=CH-COOCH3: methyl acrylate,… II – PHYSICAL PROPERTIES Esters are liquids or solides at normal conditions and they are slighty water-soluble Comparming with acids that have the same molecular weight or the same number of carbon atoms, esters have boiling points and water-solubility that are lower than that of the corresponding acids Example: CH3CH2CH2COOH Boiling at 163,50C, highly soluble in water CH3COOC2H5 Boiling at 770C, slightly soluble in water If there are differences of solubility and boiling point between esters, acids, and alcohols, it is because ester don’t form hydrogen bonding among each other and ability of making hydrogen bonding between esters and water is poor Esters have specific aroma: isoamyl acetate has the ripen bananas; ethyl butyrate and ethyl propionate have the smell of ripen pineapples; geranyl acetate has the smell of rose,… CH3COOCH2C6H5 CH3COOCH2CH(CH3)2 Figure1.1 Benzyl acetate has the aroma of jasmine Figure1.2 Isoamyl acetate has the aroma of ripe bananas III – CHEMICAL PROPERTIES Esters are hydrolyzed in acidic or basic solutions Experiment:Place 2ml of ethyl acetate in each test-tube, then and ml 20% H2SO4 aqueous solution in the second test-tube The liquids in these two test-tube separate into layers Shake the both test-tube gently, equip them with a condenser then heat gradually in a water bath for In the first test-tube, the liquid is still a 2-layer mixture; in the second test-tube, the liquid is still a 2-layer mixture, in the second test-tube, the liquid becomes a homogeneous solution Explanation: In the first test-tube, the reaction occurred: The reaction is reversible, therefore, the ester is still left, and forms two liquid layers The second test-tube, the reaction occurred as follows: The reaction is irreversible, so the ester reacts (hydrolyzes) completely The ester hydrolysis in basic solution is also called saponification Besides, ester also have reactions occurring in the hydrocarbon part(s) IV – SYNTHESIS Esters are normally syntheszed by boiling a mixture of an alcohol(s) and a carboxylic acid(s) in the presence of sulfuric acid a catalyst (esterfication) However, some esters cannot be synthesized by this methods, but are prepared by distinct methods For exemple:Vinyl acetate (CH3COOCH=CH2) is synthesized by the addition reaction between acetic acid and acetylence V – APPLICATIONS Soaps, detergents Cosmetics Biscuits ESTERS Perfumes Food additives Glues Car glasses • Because esters can dissolve plenty of substances, some eaters are uesed as solvents to separate, extract organic compounds (ethyl axetate), paint-thinner ( butyl acetate),… • Some polymers of esters are used to make plastics such as poly (vinyl acetate), poli (metyl methacrylate), … • Some esters are aromatic and non-toxic that are used as flavoring substances in food industry (benzyl formate, ethyl fomate,…), cosmetics ( linalyl acetate, geranyl acetate,…),… EXERCISES Fill T (true) or F(false) in the blanks beside each statement: a) Esters are products of reactions between acids and alcohols b) Esters are organic compounds containing a COO- group c) Saturated acyclic monofunctional eaters have the molecular formula CnH2nO2 ( where n≥2) d) Compound CH3COOC2H5 belongs to a kinds of esters e) The product of the reaction between an acid and an alcohol is an esters How many esters isomers are corresponding to the molecular formula C4H8O2? A.2 B.3 C.4 D.5 Compound X has the molecular formula C4H8O2 When X reacted with an aqueous solution, compound Y was formed that had the molecular formula C4H8O2Na The structural formula of X is: A HCOOC3H7 B.C2H5COOCH3 C CH3COOC2H5 D HCOOC3H5 Hydrolysis of an ester X that has molecular fomular C4H8O2 in the aqueous NaOH solution yielding a mixture of two organic compounds Y and Z Z has the vapor density of 23 in relation to that of hydrogen The name of X is: A ethyl acetate B methyl acetate C methyl propionat D propyl formate What are the differences between the hydrolysis of an ester in acidic and basic solution? Burning completely 7,4 grams of a singular function ester gives 6,72 litres of CO2 (under standard conditions) and 5,4 grams of water a) Write the molecular formula of X b) Warm up 7,4 grams of X in enough of the aqueous NaOH till the reaction is completed to gain 3,2 grams of an alcohol Y and an amount of salt Z Draw the structural formula of X caculate the mass of X Lesson LIPIDS • To know the definition and classification of lipids • To know chemical properties and applications of lipids I – DEFINITION Lipids are organic compounds in living cells Lipids not dissolve in water but dissolve well in non-polar organic solvents In terms of constitution, almost all lipids are complicated esters including fats (also called triglyceride), waxes, steroids, and phospholipids, In this part, only fats are considered II- FATS Concept Fats are triesters of glycerol and aliphatic acids that are called triglyceride or triacylglycerol* The aliphatic acids are monofunctional long un-branched acids The common aliphatic acids in fats are: stearic acid (CH3[CH2]16COOH), palmitic acid (CH3[CH2]14COOH), and oleic acid (cis-CH3[CH2]7CH=CH[CH2]7COOH) The structural formula of fats is: (where R1, R2, R3 are alkyl groups that are the same or different) For example: (CH3[CH2]16COO)3C3H5 : tristearoylglycerol (tristearin); (CH3[CH2]7CH=CH[CH2]7COO)3C3H5 : trioleoylglycerol (triolein); (CH3[CH2]14COO)3C3H5 : tripanmitoylglycerol (tripalmitin) * Acyl is the name of the R-CO- group that is formed by omitting the –OH group of the acid RCOOH Figure 1.4 The molecular model of the fat Fats are the main components of pork fats, beef fats, chicken fats, peanut oil, sesame oil, palm oil, and olive oil, Fi gure 1.5 Some sources of fats from vegetables and animals Physical properties At ambient temperature, fats are in liquid or solid state When the molecules have unsaturated hydrocarbon moieties, for example (C17H33COO)3C3H5, fats are in liquid state On th other hand, the molecules have saturated hydrocarbons, for example (C17H35COO)3C3H5, the fats are in solid state Animal fats, vegetable oils are insoluble in water, but well soluble in organic solvent , such as benzene, hexane, chloroform, When adding fats or oil in water, they float on top of water, it is proved that they are lighter than water Chemical properties In terms of constitution, fats are tristers, so they have general properties of esters such as hydrolysis in acidic solutions, saponification and reactions occurring at the hydrocarbon moieties a) Hydrolysis When fats (for example tristearine) are heated in dilute aqueous sulfuric acid, the hydrolysic occurs as follows: (CH3[CH2]16COO)3C3H5 + 3H2O CH3[CH2]16COOH + C3H5(OH)3 Tristearin stearic acid glycerol b) Saponification Add a small amount of a solid fat (for example tristearin) in a ceramic mortar containing an a queous sodium hydroxide solution Boil gently and stir the resulting solution for 30 minutes Cool down the solution yielding a homogeneous solution Pour 10-15 mL of saturated aqueous sodium chloride in the solution, stir gently and let it stand There is a layer of light, white solid floating on the surface of the solution That is sodium salts of alphilatic acids (CH3[CH2]16COO)3C3H5 + 3NaOH C3H5(OH)3 Tristearin glycerol CH3[CH2]16COONa + sodium stearate Because these salts are used as soap, the reaction is called saponification c) Hydrogen addition of liquid fats When heating the liquid fats, for example triolein (C17H33COO)3C3H5 in a sealed pot and bubble hydrogen through (Ni catalyst), then let the mixture stand for looling down, a solid block of tristearin is formed as the result of the reaction: (C17H33COO)3C3H5(liquid) +3H2 (C17H35COO)3C3H5(solid) (175o 190 ) This reaction is used in industry to transfer liquid fats (oil) to solid fats for easy transportation or artificial butter and to produce soaps Oils and fats have bad smell ( nasty, burnt smell) when stored for a long period This is called oil/fat rancidity The double bond(s) C=C in the hydrocarbon(s) of unsaturated acids is oxidized slowly to form peroxide(s) that causes the phenomenon The peroxide(s) is decomposed, forming aldehyde(s) that has bad smell and harms the health of consumers After being used t fty, cooking oils and fats are also oxidized partially to form aldehydes, so reusing cooking oils and fats does not ensure food safety Applications Fats have lots of applications in human life Fats are important foods for human kinds Due to complicated biochemical reactions, fats are oxidized slowly, forming CO2, H2O through which they supply energy for the body The fats that have not been used are accumulated in adipose tissues Fats are materials for the synthesis of some essential compounds for body They are responsible for ensuring the transportation and absorption of compounds that are fat-soluble In industry, a large amount of the fats is used to manufacture soap and glycerol Besides, fats are used in making some other foods such as noodle, canned food, Used cooking oil can be recycled to produce fuels EXERCISES What's a fat? What are the differences in terms of constitution and physical properties between cooking oil and animal fat? Give demonstrative examples Which of the following statements is are NOT true ? A Fats are water insoluble B Fats are water insoluble, lighter than water, and well- dissolved in organic solvents C Cooking oil and grease have the same atomic components D Fats are esters of glycerol and carboxylic acids with (a) long, unbranched carbon chain (s) Trimester of the glycerol and linoleic C17H31COOH and linolenic C17H29COOH are the components of some kinds of paints Write the condensed structural formulas of all possible trimester of these two acids with glycerol There are always small amounts of free acids in fats The number of milligrams of KOH that are used to neutralize the free acids in gram of a fat is called acidic index of the fat To neutralize 2,8 grams of a fat, 3.0 ml of a 0.1 M aqueous KOH solution were required Calculate the acidic index of the fat The total number of miligrams of KOH is used to neutralize the free acids and to saponify all the esters in one gram of a fat is called soap index of the fat Calculate the soap index of a fat sample containing tristearoylglicerol contaminated with some stearic acid that has the acidic index of Material LIPID METABOLISM IN THE HUMAN BODY Lipid is one of the basic components in food for human beings When oxidized slowly in the human body with catalytic enzymes, lipids give 2-3 times more energy than proteins and carbohydrates Because lipids are water- insoluble, they cannot penetrate through intestinal walls to feed the body Thanks to the catalytic enzymes, lipids are hydrolyzed to form glycerol and alphatic acids The glycerol is absorbed directly; on the other hand, the alphatic acids are converted to water - soluble forms by the bile to be easily absorbed through the plicas into the gut On the intestinal walls, the glycerol and the alphatic acids are combined to form new lipids The new lipids go into blood and the adipose tissues where the lipids are oxidized to form CO2, H2O and energy for the activities of the body Lesson CONCEPT OF SOAPS AND DETERGENTS • To know the concepts of the detergents • To know methods to Manufacture soaps and detergents I SOAPS Concept Normal soaps are mixtures of sodium or potasssium salts of alphilatic acids and some additives The main components of soaps are salts of panmitic acids or stearic acids Besides, the are fillers (that are used to increase soaps’ hardness to cast them into cakes), antibiotic compounds and flavorings Manufacturing methods To Manufacture soaps, people heat fats with aqueous alkaline solution in sealed tanks at high temperatures Are mixtures of sodium salts of aliphatic acids is formed as glues To separate the salts from the mixture, the table salt is added into the mixture The floated aliphatic salts are mixed with excipients and then pressed into cakes The mother liquid is used to separate glycerol that is used in many other fields Figure 1.6 A corner of the factory manufacturing soaps Today, soaps are made following this scheme Alkane Carboxylic acid Sodium salts of carboxylic acids Example: II.DETERGENTS Concept To limit the exploitation of oil animal oil vegerable oil for manufacturing soaps and to meet various needs of life, people have been synthesizing many compuonds which are not salts of sodium of carboxylic acids but they have washing features as soaps have These compounds are called synthetic detergents Manufacturing methods Synthetic detergents are synthesized from petroleum For example, the salts of sodium dodecylbenzensulfonic acids is a main component of Synthetic detergents that are manufactured following the graph: Petroleum dodecylbenzensulfonic acids Sodium dodecylbenzensulfonate How many esters are formed when heating a mixture of two carboxylic acids and glycerol (H2SO4 acid as a catalyst)? Write the structural formulas of these esters Hydrolysis (catalyzed by acids) of an ester gives glycerol and a mixture of stearic acid (C17H35COOH) and panmitic acid( C15H31COOH) with a molar ratio of 2:1 Which one of the following structures can be the structural formula of the ester? A.C17H33COOCH2 B C17H33COOCH2 C17H35 COOCH C15H31COOCH C17H35COOCH2 C17H33COOCH2 C C15H31COOCH2 D C17H35 COOCH C17H35 COOCH C15H31COOCH C15H31COOCH2 C15H31COOCH2 Evaporating 7.4 grams of a saturated, monofunction ester A gives a vapor volume that equals to the volume of 3.2 grams oxygen under the same conditions of temperature and pressure a) Write the molecular formula of A b) 7.4 grams of the compound A are saponified with an aqueous NaOH solution until the reaction is completed to give 6.8 grams of the salt(s) Find the structural formula and the name of compound A Hydrolysis of a grams of an ester X gives 0.92 grams of glycerol, 3.02 grams sodium linoleate C17H31COONa and m grams sodium oleate C17H33COONa Calculate a and m Write all possible structural formulas of X 8.8 grams of a monofunctional acyclic ester were hydrolyzed with 100 ml of an 1M aqueous KOH (just enough) to give 4.6g of an alcohol Y The name of X is: A ethyl formate B.ethyl propionate C.ethyl acetate D propyl acetate Completely burning 3.7 grams of a monofunction ester X gives 3.36 litres of CO2(under standard conditions) and 2.7 grams of water The molecular formula of X is; A C2H4O2 B C3H6O2 C C4H8O2 D C5H8O2 10.4 grams of a mixture including acetic acid and ethyl acetate react equivalently with 150 grams of a 4% aqueous sodium hydroxide solution The weight percent of ethyl acetate in the mixture equals: A.22% B.42.3% C.57.7% D.88% Chapter 2: CACBOHIDRAT Lesson GLUCOSE I PHYSICAL PROPERTIES AND NATURAL OCCURRENCE Glucose is a solid that exists as colorless crystal It is well suluble in water with sweet taste, but less sweet than sugar cane Glucose is present in almost all part off trees, such as leaves flowers, roots, … and most common in ripe fruits Particularly,there is a lot of glucose in ripe grapes, hence, it is also called grape sugar In honey there is a lot of glucose (about 30%).Glucose is also found in the body of humankinds and animals In human blood, there is a small amout of glucose with nearly constant concentration of about 0.1% II MOLECULAR STRUCTURE -The molecular frumula of glucose is C 6H12O6 The structural determination of glucose is based on the following experimental data -Glucose undergoes silver mirror reaction and is oxidized by aqueous bromine solution to yield gluconic acid These indicate that there is a CH=O group in the molecule of glucose -glucose reacts with Cu(OH)2 producing a blue solution This reaction indicates that glucose has many vicinal OH groups -glucose forms an ester with five CH3COO groups ,indicating that it has five OH groups -hexane is obtained by complete reduction of glucose,demonstrating that there are six carbon atoms in the molecule of glucose ,forming an unbranched chain So : Glucose is anacyclic multifunctional compound that contains one aldehyde group and five hydroxyl groups The stucture of acyclic glucose is as follows CH2OH−CHOH−CHOH−CHOH−CHOH−CH=O Or simplified as: CH2OH[CHOH]4CHO In fact, glucose exists mainly in two cyclicfroms: α-glucose and β- glucose( see the material section) III, CHEMICAL PROPERTIES Glucose has the properties of monoaldehydes and of polyols 1, reacting with Cu(OH)2 Experiment: add in turns to a test- tube a few drops of 0,5% CuSO soluton.1 ml 10% NaOH solution after the reaction completion ,decant the unreacted solution ,keep the Cu(OH)2 precipitate Add to the precipitate ml of 1% glucose solution gently shake the test-tube Phenomenon: the precipitate dissolves, producing a blue solution Explanation: at ambient temperature, glucose reacts with Cu(OH) , yielding copper – glucose Cu(C6H11O6)2 complex which is similar to glycerol does 2C6H12O6 + Cu(OH)2→ (C6H11O6)2Cu + H2O b , reaction producing ester glucose can form an ester containing acetate groups in the molecule when reacting with acetic anhydride ( CH3CO)2O in the presence of pyridine Properties of aldehydes a, oxidation of glucose by a solution of AgNO3 and ammonia ( sivel mirror reaction) experiment : add in turns to a clean test- tube containing ml of 1% AgNO solution , then drop to the tube drowpwise a solution of ammonia until the just formed precipitate is dissolvel again Add to the reaction mixture 1ml of 1% glucose solution Heat gently Phenomenon: The wall of the tube is as shiny as a mirror Explanation: the solution of AgNO3 and ammonia axidizes glucose to form ammoniumgluconate and silver matel deposited on the wall of the test-tube t,heat HOCH2[CHOH]4CHO + AgNO3 + 3NH3 + H2O → HOCH 2[CHOH]4COONa + 2Ag + 2NH4NO3 Ammonium gluconate b, oxidation of glucose with Cu(OH)2 in the basic condition ,Cu(OH)2 oxidizes glucose to produce solution gluconate ,copper(I) oxide and H2O HOCH2[CHOH]4CHO + Cu(OH)2 + NaOH HOCH2[CHOH]4COONa + t,heat Cu2O(orange red) + 3H2O Natri gluconat sodium gluconate c, reduction of glucose with hydrogen when hydrogen is introduced into a hot glucose solution in the presence of Ni as a catalyst,a polyol, names sorbitol, is abtained: HOCH2[CHOH]4CHO + H2 → HOCH2[CHOH]4CH2OH Sorbitol 3, fermentation reaction In the presence of an enzyme as a catalyst , glucose in solution was fermented to produce ethylic alcohol and carbon dioxide: C6H12O6 2C2H5OH + CO2 IV, SYNTHESIS AND APPLICATIONS -OH 1, synthesis In industry , glucose is synthesis by hydrolysis of catalyzed by dilute hydrochloric acid or enzyme the hydrolysis of cellulose ( in shavings ,sawdust…), catalyzed by concentrated hydrochloric acid, produces glucose which is used as a starting material for the manufacture of ethylic alcohol( see lesson 6) 2, application Glucose is a nutrient and is used as an energy drink for the elderly, children, and sick people In industry, glucose, prepared from sucrose, is used to make silver mirrors, coat the inner wall of thermos, and is an intermediate in the production of ethylic alcohol from materials containing starch and cellulose V, fructose One of the isomers of glucose is fructose that has many applications The acyclic structure of fructose is: CH2OH−CHOH−CHOH−CHOH−CO−CH2OH Fructose is a colorless crystalline substance that is well soluble in water and sweeter than sugar cane Fructose is commonly found in sweet fruits such as pineapples, mangos ,… Especially, 40% of honey is fructose, hence, honey has sharply sweet taste Similar to glucose , fructose reacts with Cu(OH) to produce a blue solution of Cu(C 6H11O6)2 complex ( property of polyols) , and adds hydrogen( hydrogenation) to give polyalcohol C6H14O6(property of carbonyl group) Similar to glucose, fructose is oxidized by a solution of AgNO and ammonia and by a solution of Cu(OH)2 in an alkaline environment This is the reaxtion of the aldehyde group caused by basic conditions: fructose is converted to glucose: t,heat glucose fructose EXERCISES 1.glucose and fructose A both can produce blue solutions when reacting with Cu(OH)2 B both contain a CHO functional group in the molecule C are two allotropes of one substance D exist in the acyclic forms The following solution are given: glucose, glycerol formaldehyde, ethanol Which one of the following reagents can be used to differentiate all of the four solution above? A, Cu(OH)2 B, Sodium C, A solution of AgNO3 and NH3 D, Aqueous bromine solution 3, What is carbohydrate ? How many kinds of important carbohydrate are there? State their definitions and give illustrative examples Which experiments can be used to prove the molecular structure of glucose? Describe chemical methods to identify each compound in the solution ò the following compounds: A, glucose , glycerol, ethanol, and acetic acid B, fructose , glycerol, and ethanol C, glucose , formaldehyde, ethanol, and acetic acid to coat a mirror , a solution ò 36 grams of glucose is heated with a stoichiometric amount ofa solution of silver nitrate and ammonia Calculate the amount of silver formed that is deposited on the surface of the mirror and the amount of silver nitrate required , given that all the reactions occur quantitatively Lesson 6: SUCROSE, STARCH, AND CELLULOSE I – SUCROSE Sucrose (C12H22O11) is the most common sugar that is found in many plants, especially in sugar cane (figure2.3), sugar beets, and flowers of jaggery Depending on the plant origins, commerial products from sucrose are called sugar cane, sugar beets, … Physical properties Sucrose is a colorless and odorless crystalline substance that has sweet taste It melts at 185 OC Sucrose is well soluble in water Its solubility increases quickly with the increase of temperature (at 20OC, 100ml of water dissolve 211.5 grams of sucrose; at 90 OC, 100ml of water dissolve 420 grams of sucrose) Molecular structure Sucrose doesn’t undergo the silver mirrow reaction and doesn’t decolorize bromine solutions This proves that sucrose doesn’t have the CHO functional group When a solution of sucrose is heated with dilute H2SO4, the resulting solution undergoes the silver mirror reachtion, because the solution after hesting contains glucose and fructose So: Sucrose is a disaccharide that is composed of one glucose moiety and one fructose moiety binding together via an oxygen atom Figure 2.3 Sugarcane – the source of sucrose Thus, in the molecule of sacrose, there is on aldehyde (CH=O) group; there are only hydroxyl (OH) groups Chemiscal properties Because sucrose doesn’t have any aldehyde functional groups, it doesn’t have oxidizing ability as glucose does, but has the property of polyols On the other hand, sucrose is composed of two monosaccharides, hence, it undergoes the hydrolysis reaction a) Reaction with Cu(OH)2 In solution, sucrose reacts with CU(OH)2 to give a solution of blue copper saccharate 2C12H22O11 + Cu(OH)2 (C12H21O11)2Cu + 2H2O b) Hydrolysis When asucrose dolution is heated in the presence of a mineral acid as a caralyst, it is hydrolyzed to give glucose and fructose: C12H22O11 + H2O C6H12O6 + C6H12O6 sucrose glucose froctose The hydrolysis of sucrose also occurs in the presence of an enzyme as a catalyst Production and applications Sugarcane Squeeze (or soak, extract) Sugarcane juice (12-15% sugar) + Limewater, filter to remote impurities Sugar solution containing calcium + CO2, filter to remove CaCO3 Sugar solution (having color) + SO2 (color bleaching) Sugar solution (colorless) Concentrate to crystallize, filter Crystalline sugar Treacle a) Production Sucrose is exrtrated from sugarcanes, sugar beets, or flowers of jaggery In Vietnam, the production procedure of sucrose from sugarcane inclodes the follwing main step: b) Applications Sucrose is importannt food of humankinds In food industry, sucrose is an ingredient for the production of cakes and candies, beverages, canned food In pharmaceutical industry, sucrose is used to dispense drugs Sucrose is a material to produce glucose and fructose via hydrolysis that are used in coating mirrors and the inner wall of thermos II – STARCH Physical properties Starch is a white amorphous solid that is onsoluble in cold water In hot water, starch bits are hydrated and swollen to form colloidal solutions, called starch solution Molecular structure Starch is one of polysaccharides containing a large number of a α-glucose chains binding together Its molecular formula is (C6H10O5)n The α-glucose chains bind together to form two forms: amylose and amylopectin (figures 2.4a and 2.4b) Amylose is ahelical polymer made of α-D-glucose units, bound to each other through α(14) glycosidis bonds Amylose has high molecular weight of about 200 000 Amylopectin has branched structures that are made up of α-glucose Each short part contains from 20 to 30 glucose units that are bound together through α(14) glycosidic bonds Different parts are connected through α(16) glycosidic bonds Amilopectin has very high molecular weight of about 000 000 – 000 000 Therefore, amylopectin is insoluble in water, as well as in other common solvents Figure 2.4 a) Molecular model of amylose b)moleccular model of amylopectin Starch (in grains, tubers) is a mixtube of amylose and amylopectin, among which the ratio of amylopectin is higher The starch chain is not long, twists to form hollow beads Starch is formed in green trees by photosynthesis Form cacbon dioxide and water, under the action of sun light and chlorophyll, starch is producted following the scheme below: CO2 C6H12O6 glucose (C6H12O6)n starch Chemical properties a) Hydrolysis When starch is heated in dilute solutions acids, glucose is obitained: (C6H12O6)n + nH2O n C6H12O6 In human and animal body, starch is hydrolyzed by enzymes to glucose b) Color reaction with iodine Experiment: Carry out the experiment as shown in the figure 2.5, the test-tube containing starch solution and I2 (b) as well as the cross section of a sweet potato + I (c) has intense bluish purple colour Figure 2.5 a) Test-tube containing 2% starch solution; b) Add a few drops of dilute I2 solution into a starch solution; c) Add a few drops of dilute I2 solution onto the cross section of a sweet potato Applications Starch is one of the fundamental nutrients of humans and several animals In industry, starch is used to make candies, cakes, glucose and glues In human body, starch is hydrolyzed to form glucose by enzyme in the intestine The most part of glucose is absorbed via the intestinal wall into blood to nourish the body; the excess is converted to glycogen by enzymes, which is stored for the body s Figure 2.6 A “chung” cake make from glutinous rice III – CELLULOSE Figure 2.7 Cellulose fibers Physical properties, natural occurrence Cellulose is a white odorless solid sudstance in form of fibers Cellulose is insoluble in water and in many other organic solvents, such a ethanol, ether, benzene,… but soluble in Schweizer’s reagent (a solution obtained when dissolving Cu(OH)2 in ammonia solution) Cellulose is the main component that makes up the plant cell wall, forming the skeleton of trees Nearly ninety eight percent of cotton is cellulose; cellulose contributes from 40 to 50% of wood by mass Molecular structure Cellulose is a polysaccharide that contains a great number of β-glucose binding together to form long chains Cellulose has very high molecular weights of about 000 000 Cellulose chains bind together to form cellulose fibers Different from starch, cellulose has only unbranched structure; each C 6H10O5 moiety contains three OH groups, so it can be written as: (C6H10O5)n or [C6H7O2(OH)3]n Chemical properties a) Hydrolysis When cellulose is heated in concentrated solutions of mineral acids, for example, H2SO4 70%, glucose is obtained: (C6H10O5)n + nH2O nC6H12O6 The hydrolysis of cellulose also occurs in animal stomach by cellulase b) Reachtion with nitric acid When cellulose is heated in a solution of concentrated nitric acid and sulfuric acid, trinitrate is obtained: [C6H7O2(OH)3]n + 3nHNO3(concentrated) [C6H7O2(ONO2)3]n + 3nH2O Cellulose trinitrate is easily inflammable and strongly explosive without producing smoke; therefore, it is used to produce smokeless gunpowder Applications Materials containing cellulose (cotton, jute, wood,…) are used directly (yarn spinning to fabricate clothes, in construction, making wooden furniture,…) or producing paper Cellulose is a material for the production af artificial fibers (such as visco, acetate), smokeless gunpowder and film EXERCISES Which one of the following statements is true? A Fructose undergoes silver mirror reaction, proving that it has a CHO functional group B Hydrolysis of cellulose produces glucose C Hydrolysis of starch produces fructose and glucose D Both cellulose and starch undergo silver mirror reaction Which one of the following statements is true (T)? Which one is false (F)? a) Sucrose is considered tobe a short part of starch b) Both starch and cellulose are polysaccharides; they differ only in the structure of the glucose moiety c) When sucrose, starch and cellulose are completely hydrolyzed, all of them produce the same kind of monosaccharide d) When starch and cellulose are completely hydrolyzed, both of them produce glucose a) Compare the physical properties of glucose, sucrose, starch and cellulose b) Find the structural relation between glucose, sucrose, starch and cellulose Mention the similar chemical properties of sucrose, starch and cellulose Write the chemical equations (if any) Write the chemical equa of the reactions (if any) in the following case: a) Hydrolysis of sucrose, starch and cellulose b) Hydrolysis of starch (catalyzed by an acid); after that, the resulting product is reacted with a solution of AgNO3 and NH3 Heating cellulose with a mixtube of concentrated HNO3/H2SO4 To coat several thermo bottles, 100 grams of sucrose were hydrolyzed, and the resulting product was used in the silver mirror reaction Write the chemical equations of the reactions that occurred Calculate the amount of AgNO3 required and the amount of Ag formed, given that all the reactions were quantitative Lesson 7: Review Structure and properties of carbohydrates I) Knowledge to remember 1) Structure a) Glucose and fructose ( C6H12O6 ) Glucose in open-chain form is both monoaldehyde and polyols CH2OH[CHOH]4CHO Fructose in open-chain form is both monoketone and polyols.It can be converted to glucose in basic environment: CH2OH[CHOH]3-CO-CH2OH CH2OH[CHOH]3CHOH-CHO b) Sucrose( C12H22O11 hay C6H11O5-O-C6H11O5) The molecule of sucrose doesn’t have a CHO functional group, but has many hydroxyl groups c) Starch and cellulose (C6H10O5)n Starch: The α-glucose units bind together to form helical chains The molecule doesn’t have any CHO functional groups Cellulose: The β-glucose units bind together to form long chains The molecule doesn’t have any CHO functional groups, and each unit has three OH groups; hence, the molecular formula of cellulose can be written as : [C6H7O2(OH)3]n 2) Chemical properties a) Glucose undergoes reactions typical for the aldehyde functional group CH2OH[CHOH]4CHO + 2AgNO3 + 3NH3 + H2O CH2OH[CHOH]4COONH4 +2Ag +2NH4NO3 Fructose also undergoes silver mirror reaction, because in basic environment, fructose is converted to glucose b) Glucose, fructose, sucrose, and cellulose undergo reactions tyical for polyols - Glucose, fructose, and sucrose react with Cu(OH)2 to produce blue soluble compounds - Cellulose reacts with concentrated nitric acid to give cellulose trinitrate [CH6H7O2(OH)3]n +3nHNO3 ( conc) [C6H7O2(ONO2)3]n +3n H2O (C6H11O5)n +H2O n C6H12O6 c) Sucrose, starch, and cellulose are hydrolyzed by acidic catalysts or suitable enzymes C6H12O5-O-C6H12O5 + H2O (C6H11O5)n +H2O C6H12O6 + C6H12O6 n C6H12O6 d) Fermentation reaction to produce ethanol C6H12O6 (aq) II) 2C2H5OH aq +2CO2 (K) Exercises To differentiate the solution of glucose, the solution of sucrose, and the solution of acetic aldehyde, which one of the following compounds can be used as reagent? A Cu(OH)2 and AgNO3/NH3 B Bromine solution and NaOH C HNO3 and AgNO3/NH3 D AgNO3/NH3 and NaOH When an organic compound was completely burnt, a 1:1 mixture of CO2 and water vapor was obtained This compound can be fermented to yield ethanol Which one is that compound? A Acetic acid B.Glucose C.Sucrose D.Fructose Describe a chemical method to differentiate among the solutions in each following sets: a) Glucose, glycerol, acetic aldehyde b) Glucose, sucrose, glycerol c) Sucrose, acetic aldehyde, starch solution From one ton of starch containing 20% inert impurities, how many kilogramsof glucose can be produced, if the total yield of the process is 75% ? Calculate the amount of glucose obtained when hydrolyzing; a) kg of rice powder containing 80% starch , the rest is inert impurities b) kg of sawdust containing 50% cellulose, the rest is inert impurities c) kg of sucrose Given that the reactions are quantitative When 16.2 grams of carbohydrate X were completely burnt, 13,44 liters CO2 ( at standard conditions) and grams of water were obtained a) Calculate X’s empirical formula Which kind of carbohydrate is X? b) 16.2 g of X is heated in acidic solutions to give solution Y When Y is reacted with an excess of a solution of AgNO3 and NH3, how many grams of Ag can be obtained? Given that the total yield of the whole process is 80% Lesson : Practical task Synthesis,chemical properties of esters and carbohydrates EXPERIMENT CONTENT AND PROCEDURE Experiment Synthesis of ethyl acetate Add ml ethylic alcohol, ml of pure acetic acid and one drop of concentrated sulfuric acid to a test tube Shake the tube well while heating it in a steam bath for - minutes at 65 ~ 70°C (or heat the reaction mixture gently on the flame of an alcohol burner) Let it cool down and pour ml of saturated NaCl solution into the test tube Make observations and write the chemical equations Experiment Saponification reaction Place in a small porcelain bowl about gram of fat (or plant oil) and -2.5 ml of 40% NaOH solution Gently boil the reaction mixture and continuously swirl it with a glass rod Add from time to time a few dmps of water to keep the volume of the mixture unchanged After from 10 minutes, add to the mixture ml of warm saturated NaCl solution and swirl the mixture Let the reaction mixture cool down and make observations Explain and write the chemical equations Experiment Reaction of glucose with Cu(OH)2 Add drops of 5% CuSO4 solution and about ml of 10% NaOH solution to a test-tube Gently shake the tube, decant the solution and keep the Cu(OH)2 precipitate Add to the precipitate ml of 1% glucose solution, gently shake the tube Make the observations Heat the test-tube, make the observations Explain and write the chemical equations Experiment Iodine test for starch Add a few drops of iodine soluuou to a test-tube containing 1-2 ml of starch solution (or add a few drops of iodine solution on the cutting surface of a fresh sweet potato or a cassava) Note the color change and explain Heat the solution for a while, and let it cool down Make observations of experiment phenomenon Explain Lesson 9: AMINES • To know the concept,classification and name of amines • To understand the typical properties of amines I CONCEPT, CLASSIFICATION AND NOMENCLATURE 1.Concept,classication Replacement of the hydrogen atoms of NH3 with hydrocarbon moieties gives amines For example: ; ; ammoniac methylamine ; phenylamine ; dimethylamine cyclohexylamine Amines usually have isomers of the carbon chains, location of the functional groups and the order of the amines For example: corresponding to the molecular formula of the C4H9N, there are the following isomers: ; ; Amines are classified in two most common ways: a, Basing on the hydrocarbon moieties, we have:acyclic amines such as CH3-NH2, C2H5NH2, , aromatic amines such as C6H5NH2, CH3-C6H4-NH2, b, Basing on the order of amines( the order of an amine is caculated by the number of the alkyl substituents with the nitrogen atom): primary amines such as C2H5NH2, secondary amines such as CH3-NH-CH3, tertiary amines such as 2.Nomenclature Amines are normally called based on the name of the functional class name (akyl/aryl with the amine function) and the substitutive name (table 3.1) Table 3.1 Names of some amines Structural formula CH3NH2 CH3CH2NH2 CH3NHCH3 CH3CH2CH2NH2 (CH3)3N CH3[CH2]3NH2 C2H5NHC2H5 C6H5NH2 H2N[CH2]6NH2 Functional class name Methyl amine Ethyl amine Dimethyl amine Propyl amine Trimethylamine Butylamine Diethylamine Phenylamine hexamethylendiamine Substitutive name Methanamine Ethanamine N-methylmethanamine Propan-1-amine N,N-dimethylmethanamine Butan-1-amine N-ethylethanamine Benzenamine Hexa-1,6-diamine II.PHYSICAL PROPERTIES Methylamine, dimethylamine, trimethylamine and ethylamine are gaseous compounds that have uncomfortable smell of urine and water-soluble Amine that have higher molecular weight are liquid or solid Their boiling points increase gradually and their solubilities in water decrease gradually with the increasing molecular weight Aromatic amines are liquid or solid and easily oxidized Standing in the air, the colorless aromatic amines are transformed to black because of oxidation -All amines are toxic Figure 3.1.Tobacco trees contain a toxic amine,nicotine III.MOLECULAR STRUCTURE AND CHEMICAL PROPERTIES 1.Molecular structure In amine molecules, the nitrogen atom can form one,two or three bonds with hydrocarbon moieties, corresponding to primary amines RNH2, secondary amines R- NH-R’, tertiary amines Figure 3.2 Molecular models: a) ammonia; b) methylamine; c)aniline Thus, amine molecules have a nitrogen atom that is similar to NH3 molecule so amines have basicity Besides, amines also have a the properties of the hydrocarbon moieties Chemical properties a) Basicity ... (C6H11O5)n +H2O n C6H12O6 c) Sucrose, starch, and cellulose are hydrolyzed by acidic catalysts or suitable enzymes C6H12O5-O-C6H12O5 + H2O (C6H11O5)n +H2O C6H12O6 + C6H12O6 n C6H12O6 d) Fermentation... scheme below: CO2 C6H12O6 glucose (C6H12O6)n starch Chemical properties a) Hydrolysis When starch is heated in dilute solutions acids, glucose is obitained: (C6H12O6)n + nH2O n C6H12O6 In human and... saccharate 2C12H22O11 + Cu(OH)2 (C12H21O11)2Cu + 2H2O b) Hydrolysis When asucrose dolution is heated in the presence of a mineral acid as a caralyst, it is hydrolyzed to give glucose and fructose: C12H22O11
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