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1、高中化学等效平衡（高中化学等效平衡（High school chemistry equivalent balanceHigh school chemistry equivalent balance）High school chemistry equivalent balance.Txt if you loveseveral people at the same time,you are young;if you love onlyone person,then you are old;if you do not love anyone,youhave been reborn.A positiv
2、e person must have a habit ofpersistence.College entrance examination,poetryappreciation,equivalent balance,default classification,2010-09-11,17:51:54 reading,4 reviews,0 types:large andmedium subscriptionsDialysis of equivalent equilibrium knowledge points and itsapplicationI.establishment of equiv
3、alent balance principlePointed out that the chemical equilibrium theory:a reversiblereaction,when the external conditions,whether it is from thebeginning of Affirmative reaction,or from the reverse reaction,or from the forward and the reverse reactions begin at the sametime,finally can reach the equ
4、ilibrium state.The state ofchemical equilibrium relates to the conditions,but not to thepath to balance.Therefore,we put in certain conditions(constant temperature,constant voltage or constanttemperature,constant volume),just starting material to jointhe same reversiblereaction different after equil
5、ibrium,thereaction mixture of any component fraction(the same volume,quality,amount of substance)are equal,so called eachequivalent chemical equilibrium balance.Two,the conditions and types of equivalent equilibriumestablishmentAccording to the conditions of establishing equivalentequilibrium,it can
6、 be divided into two categories:constanttemperature,constant pressure and constant temperature,constant volume.In the constant temperature and constantvolume,we must consider two cases of equal and unequal gasmolecular number before and after the reaction.The conclusionis:two categories and three ca
7、ses.Their classification,establishment conditions and characteristics are summarized asfollows:Explanation:for the reversible reaction of gas molecules withequal number of molecules before and after the reaction,thechange of pressure in the constant temperature and constantvolume condition does not
8、affect the movement of theequilibrium.1,constant temperature constant volume(fixed T,V)equivalentbalance(1)in T,V conditions,to change the gas volume before and afterthe reaction the reaction:if the change of initial join,aslong as the stoichiometric number of reversible reaction thanconverted into
9、balance on both sides of the same side of thesame amount of substance and the original balance is twoequivalent balance.(2)under the condition of definite T and V,the reaction ofthe volume of the gas before and after the reaction isinvariable:if the ratio of the amount of the reactants(or theproduct
10、s)is the same as the original equilibrium,two,thebalance is equivalent.2,constant temperature constant pressure(T,P)equivalentbalanceIn T,under the condition of P:if the change of initial join,as long as the stoichiometric number of reversible reactionthan converted into the left and right sides of
11、the same sideof the equation of material molar ratio and the original balanceis the same,two equivalent balance.Namely:the reversible reaction gas volume changes before andafter the reaction,the constant volume vessel to reach a stateof equilibrium,the feeding amount must be the same;constantpressur
12、e vessel to reach a state of equilibrium,the feedingamount can be different,but the investment proportion of thesame.For the reversible reaction of gas volume before and afterthe reaction,whether in constant volume container or constantpressure change,in order to achieve the same equilibrium state,a
13、s long as the proportion of material can be fed.See thefollowing table for details:Table 1 Classification of equivalent balance,establishmentconditions and resultsreactionconditionClassified constant temperature,constant volume,constanttemperature and constant pressureThe number of gas molecules is
14、unequal before and after thereactionA(g)+B(g)C(g)has equal molecular numbers before and afterthe reactionA(g)+B(g)2 C(g)reversible reactions of all gasesClassification I II IIIThe establishment of conditions of products according to themeasurement of equivalent balance coefficient of thereversible r
15、eaction equation of all push down as the reactant,the initial of the same material with two balance establishedby the same security amount two cases,equivalent.(this isessentially the same product according to the stoichiometricbalance)reversible reaction equation of all push count asreactants,two e
16、quilibrium equivalent molar ratio is the samein the two situations when the.(such as the reaction undersecond conditions:molar ratio is n times the material reactionthe first case of the ratio of the product)according to themeasurement of the reversible reaction equation of thecoefficient of push do
17、wn as reactants,two equilibrium molarratio is the same in the two under the condition of theestablishment of the equivalent.(for example,the ratio of theamount of reactants in the second case is n times the amountof reactants in the first case)The results of the two balance components n,C,100 compon
18、entsare the same:the density of gas two times balance is the same,the same substance as the reaction rate V.Two equilibriumcomponents of 100 N,C with the same component,the proportionof gas density change:two equilibrium is not necessarily thesame reaction rate V of same material is not the same.In
19、thetwo equilibrium,the components of each component are the sameas the C,and the N varies in proportion.When the two balanceoccurs,the density of the gas is the same as that of P,andthe reaction rate of the same substance is the same as that ofV.Note:the equivalent balance formula can be summarized
20、asfollows:the pressure ratio is the same;Equal capacity:if the coefficient(gas coefficient)unchanged,can be the same as the ratio.Three.The application of equivalent balance in solvingchemical equilibrium questions1.The amount of matter in different starting statesExample 1.If the temperature is con
21、stant,adding 2molSO2,1mo1O2 in a constant volume container,the following reactionsoccur:2SO2(g)+O2(g),if equilibrium,the amount of substance SO3is aMo1/L.If the material is changed at the beginning,and thequantity of the substance SO2 is expressed by a;the Brepresents the amount of the substance of
22、O2;the C indicatesthe amount of the substance in SO3;however,the amount ofsubstance SO3 in equilibrium is required to be aMo1/L,fill in the blanks below:(1)if a=0,b=0,then c=;(2)if a=0.5,then b=,c=;(3)write the relation that a,B,C should satisfy(please usethe two equation representation,one containi
23、ng only a and Cand the other containing only B and C):,.Analysis:according to the constant temperature and volumeequivalent balance conditions,meets the equation inmeasurement data is converted into SO2 and O2 of the amount ofsubstance and theoriginal start adding SO2 andO2 is equal tothe amount of
24、material.Therefore,a+c=2,2b+c=2 should besatisfied and thus available(1)in c=2,(2)b=0.25,c=1.5.thinking if the volume fixed container in the above problemis changed into a pressure invariant container,the same answerto the above question(third small questions,parentheses,text,removal),then what is t
25、he situation?(reference answer:C 0;b=0.25,C=0;a:b=2:1,C=0 or a=b=0,C 0)2,the judgment of equivalent balanceExample 2.in a constant temperature and constant pressurevessel,the A and B gases can establish the followingequilibrium:2A(g)+2B(g)C(g)+3D(g)is now balanced from two paths:I.the startingquanti
26、ties of.A and B are 2mo1;the initial quantities of II,.Cand D are 2mo1 and 6mo1,respectively.The following statementsare true:()When the A,I and II two pathways finally reach equilibrium,the composition of the mixture gas in the system is the sameWhen the B,I and II two pathways finally reach equili
27、brium,the percent composition of the mixed gases in the system isdifferentWhen C reaches equilibrium,the average relative molecular massof the mixture gas is the same as that of pathway 1 and pathwayIIWhen D reaches equilibrium,the gas density of pathway I is 1/2of pathway IIAnalysis:the establishme
28、nt of chemical equilibrium hasnothing to do with the reaction path.It can be equal to theinitial amount of A and B to be 4mo1(the extreme transformationis carried out,and the complete reaction of 2mo1 and 6mo1D isconverted into 4mo1A,4mo1B).Join 2mo1A 2mo1B,volume VL,constant temperature and pressur
29、e,then add 2mo1A and 2mo1B volume is changed to 2VL,A,B visible,the initial amount of 4mo1 is equivalent to two A,the initialB was 2mo1 under the same conditions of superposition,balance,concentration of the same objects of the same the same,conversion rate,average molar mass and density are the sam
30、e.So choose the A and C options.3.Judgment of moving direction of chemical balanceExample 3.at a certain temperature,in a variable volumecontainer,react with 2A(g)+2B(g)When 2C(g)reaches equilibrium,the contents of A,B and C are4mo1,2mo1 and 4mo1,respectively.Keep the temperature andpressure constan
31、t,The amount of substance in the three of the equilibrium mixtureis adjusted as follows)A.were halved,B.doubling,C.increased,1mo1 and D.decreasedby 1mo1Analysis:under isothermal and isobaric conditions,thematerial according to the stoichiometric reaction equationnumber into a reactant or product,the
32、 molar ratio is consistentwith the equivalent balance ratio of the three options A,B for2:1:2,and in the same proportion,equivalent balance,balancedoes not move.C can be expected to be added in the two step,adding 1molA,0.5mo1B,1mo1C for the first time,when thebalance does not move,second times befo
33、re the addition of0.5mo1B(the one-time add 1mo1 and equivalent),increased theconcentration of reactants,balance.D is reduced by 1,can alsobe envisaged as the two step:first reduce 1mol,A,B,reduce0.5mo1,C,reduce 1mo1,at this time balance does not move.Bis now reduced by 0.5mo1,reducing reactant conce
34、ntration andbalancing left shift.The answer is the C option.4.The conversion rate(or volume fraction)of a substance whenthe same reaction begins at different equilibrium statesExample 4.in the same volume of a,B and two containers,a isequipped with SO2 and O2 each 1g,B is equipped with SO2 andO2,eac
35、h 2G,at the same temperature reaction:2,SO2+O2 2SO3,and achieve balance.In this process,if the conversionrate of SO2 in a vessel is p%,the conversion rate of SO2 inthe container BA,equal to p%B,greater than p%C,less than p%D,can notbe determinedThis problem is much simpler if the applied process hyp
36、othesisand the equivalent equilibrium principle are applied,The process of change is assumed as shown in the followingfigure:Equilibrium 1 and equilibrium 2 are equivalent equilibrium,andthe content and conversion rate of each substance are equal.Balance 2The balance 3 is the pressurization process,
37、the balance movesto the right,and the content and the conversion rate of eachsubstance increase,that is to say,the conversion rate of SO2in the container is greater than p%,so the B option is selected.5,the comprehensive application of equivalent balanceknowledgeExample 5.I.under constant temperatur
38、e and constant pressure,the following reaction occurs in a variable volume vessel,A(gas),+B(gas),C(gas)(1)if the 1mo1,A,and 1mo1 B are added to the balance at thestart,the a mo1 C is generated,and the amount of the substancein the A is mo1.(2)if the 3 mo1 A and the 3mo1 B are added at the beginning,
39、when the equilibrium is reached,the amount of the substancethat produces C is mo1.(3)if the xmolA,2mol,B and 1 mo1 C are added at the beginning,when the equilibrium is reached,the amount of A and C is y,mo1 and 3amo1,then x=,mo1,and y=Mo1.The average B,the amount of substance(an optional number).The
40、 reason for this judgment is that.(a)greater than 2mo1(b)equal to 2mo1(c)less than 2mo1(d)may be greater than or equal to or less than 2mo1.(4)if the re-entry of a 3 mo1 C in a(3)equilibrium mixture,when the equilibrium is reached again,the amount of substancein the C is.If the temperature remains c
41、onstant,the reaction occurs in acontainer of the same volume and volume fixed before thereaction(1).(5)start by adding 1 mo1 A and 1 mo1 B to B mo1 C after thebalance arrives.B and a(1):the comparison(optional a number).(a)a b(c)a=B(Ding)can not compare the size of a andB;the reason for this judgmen
42、t is that.Analysis:this title is designed to meet the conditions,theclassification of equivalent balance III,(1)can be calculateddirectly for the amount of substance A(1-A)mo1;(2)the A,B of the amount of substance(1)is three times of A,the amountof B material,C generation the amount of substance sho
43、uld bethree times that of 3AMo1;as a result of(3)the reaction is balanced,the amountof substance C is 3 a mo1,so it is equivalent to the initialaccession of A and B,each 3mo1 should be(x+1=3)x is 2;in equilibrium,the amount of substance in A isthree times as much as(1).That is,3(1-A).The amount ofsu
44、bstance in B depends on the amount of substance C inequilibrium,the amount of 3A mo1 and the amount of substanceinitially added to C 1Mo1 relationship.(4)the balance established under theconditions is equivalent to(1),so the amount of substance inC is equal to(1),a/(2-A).Answer:(1)(1-A),(2)3a,(3)2,3
45、-3,a,Ding,if 3A 1,thequantity of B is less than 2 mo1;if 3a=1,the amount of B isequal to 2Mo1;if 3A B.0|share:reading(4)|comments(0)|references(0)|ReportI have an appointment with the princeThe history of todays poetry appreciation in the collegeentrance examinationI have an appointment with the prince,2008-09-11 13:23:46related articlesRecent reader