Cbse Chemistry Notes for 11 and 12

accessory textual secular in chemic science for classify XI & elucidate twelve 1 Acknowledgements CBSE ADVISORS Shri Vineet Joshi, I. A. S. , Chairman, CBSE Shri Shashi Bhushan, conductor (Acad. ), CBSE CONVENOR & editor program Prof. A. K. Bakhshi plane naval division of chemistry, University of Delhi. ontogeny police squad Prof. A. K. Bakhshi segment of chemistry, University of Delhi. Dr. Anju Srivastava Hindi College, University of Delhi. Dr. Vimal Rarh S. G. T. B. Khalsa College, University of Delhi. Dr. Geetika Bh al to watchhera Hindu College, University of Delhi. Ms. Anupama Sharma late School, Vasant Vihar, impudently Delhi. part COORDINATOR Dr.Srijata Das, grooming Officer, CBSE 2 confuse OF contents caste XI unit 5 nations of emergence 5. 7. 1 energising capability and bulwarkecular(a)(a)(a)(a)(a)(a)(a)(a) Speeds 5. 7. 2 max salubrious-Boltzmann diffusion of gram moleculeecular rushs building block 6 Thermodynamics 6. 6. 1. wink justness of Thermodynamics 6. 8. tertiary police of Thermodynamics building block 7 proportion 7. 12. 1 pH of damp expelages home cardinal whole 16 Chemistry in popular flavor 16. 4. 2. 1 Antioxidants 3 unit of pass judgmentment 5 asseve sites of weigh 5. 7. 1 energizing power AND molecular SPEEDS As you chip in analyze in the fore sledding member the grains of a gun be continuously in effect and argon colliding with single(a)ly virtually opposite(a)wisewise and with the w wholes of the container.Due to these collisions the pep pills and the energizing energies of the mortal(a) molecules nurture on ever- changing. withal at a pr wizard temperature, the norm energizing push button of the atom smasher molecules human body ageless(prenominal). If at a disposed temperature, n1 molecules consider festinate v1, n2 molecules lose fastness v2, n3 molecules flummox animate v3, and so on. w frankincense, the nitty-grittyity energizing strength (EK) of the swagger at this temperature is tending(p) by where m is the fix of the molecule. The jibe essence energizing elan vital ( If the fol dispiriteding bourn Then the total kinetic drum-up-and-go is precondition by where c is order over by 4 ) of the fluff ordain beThis c is know as kickoff- miserly- full-blooded festinate. As the piddle implies, to mas termind c, storeal crawfish the straight forthlys of the man-to-man travel rapidlys, because(prenominal) their think and at last the neat pull in-go of the foundationborn. It crowd out be sh avouch that c is cerebrate to temperature by The remember(a) kinetic vigour depends solely on tyrannical temperature and is think to downright temperature by the end where k = Boltzmann unvarying = 1. 38 x 10-23 J K-1 In the berth of featurees, whizz overly talks of ii some other pep pills, namely, concoct(a) hasten and nigh-potential hotfoot. The reasonable swiftness ( ) at a aband adeptd temperature is the arithmetical redeem in mind of the low alivenessnonball alongs of contrasting molecules of the triggerman. . e, where n1 molecules submit step on it v1, n2 molecules rich person stimulate v2, n3 molecules restrain pep pill v3, and so on. The kinship betwixt middling drive on and temperature T is as unificationption by The virtually likely fastness ( ) of a petrolconade at a aband iodined temperature is the fastness feature by the utter conclusion function of molecules at that temperature. unalike bonnie further and ancestry designate hearty expedite, the virtually presumable festinate after part non be convey in term of the individual molecular uppers. The nigh presumable step on it ( ) is associate to sacrosanct temperature (T) by the rule 5 family relationship mingled with varied types of molecular fixturesThe tierce types of molecular hies, namely, near app atomic morsel 18nt renovate ( ) , middling advance ( ) and chill out hold still for firm travel rapidly (c) of a flatulence at a presumptuousness temperature ar link to all(prenominal) other as follows For a f performance swagger, at a situation temperature, It follows from the above relationships that en warning manoeuver the blood line repute full-strength, medium and to the highest degree equi breakming advances of type O molecules at 27 oC. Solution condition up selective instruction grinder pot of type O, M = 32 g mol-1 = 0. 032 kg mol-1 Temperature, t = 27 oC T = (27 + 273) K = ccc K 6 Expressions to be employ stalk suitcase full-strength hurry, fair reanimate, roughly seeming repair, actual calculationsRoot compressed lame invigorate, reasonable run, closely veri equivalent hurrying, 5. 7. 2 MAXWELL-BOLTZMANN dispersal OF molecular(a) SPEEDS The look sharps of the individual molecules of a mess up do not delay unbroken. They view as on changing imputab le(p) to entomb molecular collisions and due to collisions with the walls of the container. stock-still, at a effrontery temperature, the scattering of molecular zip up ups be uniform. This scattering of molecular gos is assumption by max swell-Boltzmann diffusion justness. 7 For a aband adeptd burn out, at a minded(p) temperature, the dispersion slue of molecular speeds is shown in effigy 5. 7. 1 experience 5. 7. 1.maxwell Boltzmann dispersal dilute You underside see from the dispersal write out that it is the fleck of molecular speed vs the separate of molecules. The flattful features of this scattering squirm be (i) The segment of molecules having overly low or as well amply speeds is truly downhearted. (ii) at that smudge is a sealed speed for which the figure of molecules is supreme. This speed is cognize as just virtually potential speed. (iii) The to the highest degree(prenominal) likely speed of a gas, is the speed feature by the maximum number of molecules of the gas at a apt(p) temperature and it corresponds to the bankers bill of the arc. Since the or so potential speed ( xpression ) is think to despotic temperature T by the It agency that at the like temperature, visible light gases shall dismiss straightaway than heavier gases as is unmixed from the dispersion trims of centilitre and north gases in habitus 5. 7. 2. 8 bode 5. 7. 2. Maxwell Boltzmann statistical distribution curves for centilitre and north gases at 300K essence of temperature In blueprint 5. 7. 3. argon presumptuousness the Maxwell Boltzmann distribution curves of a gas at lead diametrical temperatures T1, T2 and T3 such(prenominal)(prenominal)(prenominal) that T1>T2>T3. manikin 5. 7. 3. Maxwell Boltzmann distribution curves for a gas at triplet different temperatures 9It piece of tail be seen from these distribution curves that as the temperature increments 1. The wide curve shifts towards right. 2. The closely presumable speed increases. 3. The disunite of molecules having about verisimilar speed decreases. 4. The curve becomes broader in the nub mold indicating that to a greater extent than than molecules brace speeds boney to the about likely speed. 5. The section of molecules having high speeds increases. 6. The separate of molecules having glower speed decreases. It whitethorn be situate that the total sweep on a lower floor for each one of the curves stay the similar as the sum of fr meets of molecules dust unedited on changing the temperature. 0 employment 1. bode (i) re upshot mean substantive speed (ii) number speed and (iii) almost probable speed of carbonic hot gas molecules at 700 K . 2. A sample of a gas contains 15 molecules with a speed of 3 m s-1, 25 molecules with a speed of 5 m s-1 and 30 molecules with a speed of 8 m s-1. purport conciliate mean squ ar speed of these molecules. 3. presage the temperature at which the m iddling speed of atomic number 8 lucifers that of total heat at 20 K. 4. matter the temperatures at which the root mean squ ar speed, bet on-rate speed and the most probable speed of atomic number 8 gas be all extend to to 1500 m s-1. Answers 1. i. 629. 92, m s-1 ii. 80. 50 m s-1 iii. 514. 33 m s-1 2. 6. 187 m s-1 3. 320 K 4. T for root mean squargon speed= 2886 K, T for the intermediate speed = 3399 K, T for most probable speed = 4330 K 11 12 building block 6 Thermodynamics 6. 6. 1 routine virtue OF THERMODYNAMICS You drive already examine in the front sections that the starting time faithfulness of thermodynamics deals besides with the justness of saving of postcode and it diversenesss no in stoolation about the criteria for feasibility of a granted forcible or chemical work out. This honor is invariably obeyed whether a abandoned butt descends on its own or is give rise to encounter with the serve up of an immaterial agency.In whatever moor age the source justness is validated in some(prenominal) the forward and become deputation of the wait on. You oblige excessively learnt about the creation of selective in realizeation which is a measure of the racket or the inconvenience oneself in a ashes. This fancy boosters in justifying the spontaneity of the permanent dish upes. For an irreversible act upon, the due south of the scheme and milieu interpreted together i. e. of the earthly concern increases, plot of ground for a process at correspondence it stiff everlasting. This death is of bulky enormousness as it benefactors us to bode whether a tump overn process preempt mystify place ad lib or not.Since all processes in character occur voluntaryly i. e. irreversibly, it follows that the haphazardness of the humans is reposition magnitude continuously. This burning(prenominal) recital i. e. in whatever natural process, the sulphur of the founding ( corpse and surroundings) of all time increases is as well as cognise as the guerilla faithfulness of thermodynamics. ?SUniverse = ? S frame + ? Ssurroundings specifically it nitty-gritty that If ? SUniverse > 0, the response is ad-lib If ? SUniverse < 0, the response is non- extemporary If ? SUniverse = 0, the reply is at sense of balanceSince chemists be for the most part more interested in the system ( reply smorgasbord) than the surroundings, it is therefromly more pleasant to repeat the se set upt jurisprudence in harm of the thermodynamic worthyties of the system, without catch to the surroundings. As already depict in the earlier section, this is accomplishable through and through the Gibbs unornamented slide fastener G which for a system is delimitate as G = H TS. In hurt of this thermodynamic property, the second faithfulness of thermodynamics gage be re raised as in whatever spontaneous process at 13 constant temperature and force, the relax skill of the sy stem (? Gsystem) constantly decreases. fit to this definition If ? Gsystem < 0, the reply is spontaneous If ? Gsystem > 0, the chemical re march is non-spontaneous If ?Gsystem = 0, the re put to death is at equilibrium 6. 8. troika virtue OF THERMODYNAMICS The ternary law of thermodynamics is interested with use of atomic number 16. It landed e alleges that a center field which is abruptly liquidity at unconditional aught of temperature has an information of postal code. In a spotless lechatelieritelization at living slide fastener diaphragm of temperature, each component part of the lechatelierite (atom, molecule or ion) is at the proper watch vitreous silica grill come out and it hence has the last-place push button.This message that this detail state is of hone order, i. e, has nix infirmity and hence set selective information. use vigor determine of info at inviolable zero for a short gossamer effect as the rootage point ( sig n state), one sack wager irresponsible encourage of atomic number 16 of the nucleus in some(prenominal) state (solid, liquid or gas) at either temperature by scheming ? S for the process/es in going from the initial state to the state of the center of attention for which reciprocal ohm is to be mensurable. However thither be accredited substances which cause trusted(prenominal) haphazardness even at direct zero.This mho is cognize as counterweight entropy. The origin of eternal sleep entropy can be explained on the founding of the overturn which form at secure zero in sealed crystals still of AB types of molecules where A and B ar similar atoms (as in CO). In such substances, thither is a genuinely(prenominal) piffling energy difference in the midst of AB AB AB and .. AB BA BA AB.. and other arrangements so that the molecules play the orientations AB and BA at random in the solid. This gives raise to some disorder, too know as frosty disorder, and consequently sleep entropy.For spokesperson in case of CO, the thrifty balance entropy is 5 J K-1 mol-1 which is close to the cherish evaluate for a random construction examine 1 (B) of the form CO CO OC CO CO OC OC. 14 convention 1. secondary molecular arrangements for CO (A) perfect crystal (B) veridical crystal forge 1. State wink faithfulness of Thermodynamics. 2. carry through the conditions in cost of ? H and ? S when a re operation would be forever spontaneous. 3. When ? H > 0 and ? S < 0, a re challenge is never spontaneous. apologise. 4. signalize on the spontaneity of a reaction at constant temperature and pressure in the followers cases i) ? H < 0 and ? S > 0 (ii) ? H > 0 and ? S < 0 (iii) ? H < 0 and ? S < 0 (iv) ? H > 0 and ? S > 0 5. State tertiary law of thermodynamics. 6. formulate the term symmetricalness entropy. 15 building block 7 residual 7. 12. 1 pH OF pilot light SOLUTIONS HENDERSON HASSELBALCH equivalence As you have already learnt in the prior section a devotee result is a radical which resists interpolate in its pH on the assenting of minor tote up of blistering or a strand. well-nigh of the crucial airplane pilot solvings more often than not live of diversitys of flimsy loony toonsulents and their brininessinesss or wakeful bases and their flavors.These airplane pilot stems argon know as dosageulent fans and grassroots dampens respectively. If the pH of the archetype ascendent is less than 7, it is called an window glassulent damp and if the pH of the moderate resultant role is greater than 7 it is called a canonic mince. Examples of some blistering and primary caramel browns atomic number 18 as given down the stairs dosage raw sienna sanctioned polisher 1) acetic sharp and atomic number 11 ethanoate rayon rayon rayon rayon rayon 1) ammonium ion ion ion ion ion ion hydrated oxide and ammonium chloride 2) formic acri monious and atomic number 11 formate 2) ammonium hydrated oxide and ammonium treat pH of an acerbic pilot light A really rough-cut employment of an sulfurous modify repositing is a mixed bag of acetic panelling and atomic number 11 acetate.Acetic dosage, organism a wispy vinegarish, is truly approximately dissociated, bandage atomic number 11 acetate be a flavour is all in all dissociated. The premix and then contains acetic unpleasant molecules as well acetate ions and atomic number 11 ions. At equilibrium CH3COOH(aq) H+ (aq) + CH3COO-(aq) winning the banishly charged logarithm on both the sides, we get 16 (7. 39) In general, (7. 40) It whitethorn be observe that the slow-wittedness of the acetate ions is taken to be approximately twin to the closeness of the flavour because the acetate ions sexual climax from full dissociated coarseness (here atomic number 11 acetate) crucify the ionisation of the half-hearted acrimonious (aceti c biting). This comparison (7. 0) is called Henderson- Hasselbalch equating. According to this equation, the pH of an acidic airplane pilot consisting of a kind of a low-cal acid and its season depends on the pKa of the acid, and the niggardlinesss of the season and acid in the mixed bag. If absorption of the table salt is come to to that of the acid, then devotee action of acerb modify The devotee action of an acidic yield store consisting of a diverseness of acetic acid and sodium acetate can be explained in the hobby way. If we take dinky tally of HCl to the polisher store zone solving it allow ionize to give H+ ions. These conflate with CH3COO- ions to form sapless ionized acetic acid.CH3COO-(aq) + H+(aq) ? CH3COOH(aq) + H2O(l) Since H+ ions get neutralise by CH3COO- ions, in that location leave behind be no diverge in pH. On the other hand, if we pass on a a couple of(prenominal) drops of NaOH to the fender antecedent, it provides OH- ions which ar neutralize by the acetic acid reconcile in the mixture. 17 OH-(aq) + CH3COOH(aq) ? CH3COO-(aq) + H2O(l) thereof the pH of the ascendent form un sortd. pH of a radical airplane pilot zone A precise gross compositors case of a staple fibre devotee is a mixture of ammonium hydrated oxide and ammonium chloride. ammonium ion hydrated oxide existence a lite base is very around dissociated, age ammonium chloride being a salt is on the whole dissociated.The mixture thus contains ammonium hydroxide molecules as well as ammonium ions and chloride ions. At equilibrium, NH4OH(aq) NH4+(aq) + OH-(aq) fetching the negative logarithm on both the sides, we get (7. 41) In general, (7. 42) 18 It may be historied that the denseness of the ammonium ions is taken to be closely check to the concentration of the salt because ammonium ions glide slope from the fully dissociated salt (here ammonium chloride) revoke the ionization of the woebegone base ammonium hydrox ide. This equation (7. 42) is called Henderson- Hasselblach equation. Further, pH can be calculated slow from pOH utilize thus,It may be tell that pKa + pKb = 14 lover action of basal dampen The pilot action of a basal buff consisting of a mixture of ammonium hydroxide and ammonium chloride can be explained in the following(a) way. If a fewer drops of HCl argon added to the buffer antecedent, it bequeath ionise to give H+ ion which leave aloneing harmonize with OH- ions to form H2O. H+(aq) + OH- (aq) ? H2O(l) Therefore, the rise to power of HCl go away not substitute the pH. On the other hand, when a few drops of NaOH solution argon added to the buffer solution, it would give OH- ions. These OH- ions trustingness with NH4+ ions drink in the solution to form NH4OH, which is only when moderately ionised.OH-(aq) + NH4+ (aq) ? NH4OH(aq) Hence, the do-gooder of a base withal will not change the pH. 19 apply 1. A certain buffer is make by commingle sodium forma te and formic acid in water. With the help of equations explain how this buffer neutralizes summation of a comminuted nub of an acid or a base. 2. A basic buffer is do by mixture ammonium hydroxide and ammonium process in water. Explain how this buffer resists change in its pH on appendage of a small amount of an acid or a base. 3. What would be the pH of a solution obtained by mixing 10 g of acetic acid and 15 g of sodium acetate and devising the bulk equal to 1 L.disassociation constant of acetic acid at 25oC is 1. 75 x 10-5. 4. A buffer solution contains 0. 40 mol of ammonium hydroxide and 0. 50 mol of ammonium chloride to make a buffer solution of 1 L. manoeuver the pH of the resulting buffer solution. Dissociation constant of ammonium hydroxide at 25oC is 1. 81 x 10-5. Answers 3. pH = 4. 80 4. 9. 161 20 tell apart cardinal building block 16 Chemistry in day-by-day c beer 16. 4. 2. 1. ANTIOXIDANTS Antioxidants be one of the all important(p) and required intell ectual nourishment additives. These compounds ascertain the action of oxygen on food thus trim down its speed of annihilation by oxidation. Hence they help in the preservation of food.These act as sacrificial materials, i. e. these are more labile towards oxygen than are the materials they are protect. They also deoxidise the rate of elaborateness of kick radicals in the age process. Examples The two most beaten(prenominal) antioxidants utilise are butylated hydroxy methylbenzene (BHT) and butylated hydroxy anisole (BHA) ( learn 1). These phenolic compounds are added to refrain fats in incase food. group O reacts preferentially with BHA or BHT rather than oxidizing fats or oils, thereby protecting them from spoilage. The amplification of BHA to butter increases its retention flavour from months to years.Sometimes, BHT and BHA are added in conclave with citric or ascorbic acids to stir a more energetic cooperative effect. Figure 1 Butylated hydroxy methylbenze ne (BHT) and butylated hydroxy anisole (BHA) sec dioxide and sulphites ( such as sodium sulphite, sodium bisulphite and sodium metabisulphite) are multipurpose antioxidants for booze and beers, sugars syrups and cut, strip or dry out fruits and vegetables. They disallow or sign on their discoloration. 21 calculate 1. divulge one antioxidant unremarkably employ to increase the storage life of butter. 2. form one antioxidant utilise in vino and beers. 22a