Lecture 14. Aqueous Equilibria Pt. 3.


Formal Metadata

Lecture 14. Aqueous Equilibria Pt. 3.
Title of Series
Part Number
Number of Parts
Arasasingham, Ramesh D.
CC Attribution - ShareAlike 3.0 USA:
You are free to use, adapt and copy, distribute and transmit the work or content in adapted or unchanged form for any legal purpose as long as the work is attributed to the author in the manner specified by the author or licensor and the work or content is shared also in adapted form only under the conditions of this license.
University of California Irvine (UCI)
Release Date

Content Metadata

Subject Area
UCI Chem 1C General Chemistry (Spring 2013) Lec 14. General Chemistry -- Aqueous Equilibria -- Part 3 Instructor: Ramesh D. Arasasingham, Ph.D. Description: UCI Chem 1C is the third and final quarter of General Chemistry series and covers the following topics: equilibria, aqueous acid-base equilibria, solubility equilibria, oxidation reduction reactions, electrochemistry; kinetics; special topics. Index of Topics: 0:00:00 Equilibria Review 0:03:44 Calculating Ksp 0:10:40 Precipitation of Solubility Product 0:14:35 Complete Ion Equation 0:26:40 Precipitation Reaction 0:38:29 Calculating Concentration at Equilibrium 0:46:47 Common Ion Effect
Lecture/Conference Meeting/Interview
OK but does anybody have any questions before it began all right so that as a member we have now moved on to looking at the 3rd class of equilibrium equations or equilibrium and we're looking at solubility and we said equilibrium constants that describes the solubility of insoluble slightly soluble marginally soluble salts recalled solubility product constant OK and we said that 1 way for you to figure out where the assault is going to be soluble or insoluble is to use the solubility rules and I gave you a copy of the solubility world and I said you can use that to figure it out the other way to figure out whether it's going be insoluble and not because of its insoluble it will have a case the value in this case the values and will really small there the order of 10 to the negative something that didn't intend to make a 17 10 to negative 18 34 Cincinnati 42 and so on to these are highly insoluble substances now I also wanted to recognize that there is a parallel between what we've been doing when we looked at the gasses and bases and solubility now in solubility we look at solubility remember when let dealt a weak acid we talk about Percent Association on the amount spent associated alright the amount that associated the amount the decomposed is always the change that we're looking at it's always acts are so the amount that dissociated that's right in solid product calculations the amount associated is always call more solubility cellulosic optimally solubility it's really the amount of associating with a lot of problems before we've capping amount that associates now we're going to use the term in this topic will then use the term Moeller solubility OK and often because we're dealing with precipitates we just solid we usually get better not in terms of all solubility but we give in terms of GM solubility because we're dealing with solids are right and precipitation is a solid and therefore the amount that is all is also given in terms of grams per liter and so we call that GM solubility so last this
calculation we took silver chloride and you takes chloride and place it in water and demand associated is the molar solubility and if you want to convert all solubility to grant solubility all you have to do is multiplied by the mall the amassed so the unit from all the soluble removed malls Polydor unit for GM solubility would be grams per liter that centered we can wanted to taking a few examples of applying this and problems and let's move on to the 2nd problem that's your hand out and sell you know the previous example that we looked at last time I was using beginning the KSE and asked to calculate more solubility and GM solubility and can now whereas the movers in this problem so remains is a red solid that dissolves in water and to the extent of . 0 9 2 grams per 25 degrees Celsius calculate speak alright so it isn't exactly the difference as the opposite of what we did in the previous problems so remember they were going to deal with an equilibrium set up I unit have to be more leader we need to know the amount and associated or the molar solubility so I need to 1st convert GM solubility To Moeller solubility so they gave us GM solubility and we know that the GM solubility is 0 . 0 9 grams per liter of AEG to see 4 if I wonder calculated Moeller solubility that would be 0 . 0 2 9 grams per liter at the G 2 0 4 and eyeglasses somehow conveyed to moles member How would you can wear a grant of substance to the malls of a substance would you need to do is divided by the mall amassed so we you look at the formula you have to silver you have a call me India for oxygen is tapping the mall a massive that compound and this time you have to divide because that's how you kilograms to malls and calculate the mall amassed it comes out to be 331 . 7 3 Grammys of a G 2 0 4 and if you work that out that comes out to be 8 . 7 times 10 to the negative 5 malls per leader of the G 2 the now keep in mind that this is the amount that associated up problems this would be the acts are right so we figured out the amount and dissociated and that is the mall's solubility now we have to do is set up the equilibrium expression remembered as an equilibrium you have to use a quorum expression and so on we're dealing with AEG to CRO for this is the precipitated or the insoluble substances and when it establishes equilibrium water with a small amount of associates and so now it's very important that you know how to write the the charge appropriate charge for each of the species that were looking at the you see that you have still work and then call made his apology atomic and so when you write this it's important that you write it and you have the appropriate charges and not only that but there's charged balance because I examine if you do not write this expression correctly you will get it wrong because I do want to emphasize the need to know how to write the balanced equation are right with the appropriate species that dissociated so we know that we have sold our marriage to figure out what is the Charger that's still OK to look at as the 2 silver and so you have to solve varieties and then on the other side you have crawled made an iron and a charge of Coleman and fixed all right and so it's 2 minor so we know that it's silver has have a plus-one charge now usually we set last Saturday to what they all have cost when charges hearing group to the periodic table they all have lost 2 charges all right did dealing with transition metals they will have variable charges entered the transition metal then you have to turn to the camera and the Anaheim to figure out what the charges on the cattle arrived and so from that in what the charges the Carolinas and so this would be your balanced equation and our goal is to figure out what this years so we know at equilibrium this does not appear in the womb expressions of what is going to be blank on the side we know that it associates and you end up with 2 at this would be yes that is so that means I know should be equal the concentration of Sylvia Plath raises Part 2 times the concentration of CRO for 2 minus which gives me too x squared times not to explain these boys square on writes a 4th squared times acts will be for execute their 5 I want have to kiss the each of the 4 times 8 . 7 times tent donated by taking the power to be cases you do the math that it comes out to be 2 . 6 times 10 to the negative 12 now you can include a unit by this if you wanted to and this is multiple leader this is in multiple leader Sao there's something more skewed Polydor clearly on because we had no clue we've got in the habit of leaving out the units for the claimant constant you don't include the units that's OK to our right so that was the you can't speak any questions at this point so that deals were looking at equilibrium and his speaking now all the examples that we looked up at up to this point is where you take something that's insoluble so you can look up the solubility rules and pick up a substance that insoluble slightly soluble margin soluble and if you put it in water and you know that kind of precipitated the sink to the bottom and you and establish an equilibrium and you can solve it this way again no turns of that another way of generating a precipitation is actually to take advantage of a reaction to generate precipitation cities all right so you can have a reaction that takes place that forms the precipitate instead due in solution and then you can establish that it wouldn't solicited examples where now we will have a reaction in followed by that reaction and you're going to have any clothing being established OK so when you look at precipitation and I solubility product and other taken examples so we're going to look at an
example where the let's say we have to react and there have 2 the crews are right and in and let's say we have Silverman nitrate so this is a soluble salt How do we know it's a soluble salt solubility rules tells me that all nitrates a soluble are right regardless of what they can is all nitrates a soluble so I know this is soluble salts and this is a soluble salt water line it associates completely sign on reality In solution what I had is the salt dissolved in water completely disassociated and so unless I have silver and nitrate that have dissociated completely nobody here let's say I have sodium chloride and sodium chloride is also a soluble salts right and so I know that that in reality this solution has sobered by the sodium and chloride ions dissociated completely again now the combined these 2 solutions and by combining these 2 solutions the incident I combine them can you see that what I'm going to have this nitrate ions sodium ions and minus so that instead that combine them you can see that now I have 4 lines and solutions so no 1 can do is I look at these 2 combinations I know that sodium and chloride a soluble I know silver nitrate soluble now I look at the other combinations Jonesy that sodium and nitrate will be soluble or because we know the solubility rules tells us that group 1 that lines are always soluble and we know nitrates are always soluble so the and Kanye I combination will always be soluble in would associate completely right now look at the other combination which is still there and chloride and we know that according to rules you look at the most of chloride would we know that all alright the soluble accepted the cannot find a silver mercury elected and so silver is 1 of those that is insoluble so what we know it now view combined silver and chloride the attraction for each other is much greater than the attraction for wandered and they come together did you and insoluble precipitated this will give you an insoluble precipitate OK so the net result is that I start with 2 soluble substances when I combine them together now I wind up with a precipitate all right and we call this a precipitation reactions to defend so this is called of precipitation reactions and the
purpose of addition reaction if you want a ride the complete ionic the equation right will wind up with that in each of our reactants is soluble so we have silver and nitrate and sodium and chloride and when you combine them and now we know that the attraction for so chloride is greater than the attraction for water so you can end up with a precipitate so this is is the precipitated phase excuse me in the laboratory it's it's conventional if you wanted to use abbreviation for precipitated it means no PPT OK so you follow precipitate and you have you know that sodium nitrate is completely soluble and so this is where the complete financial equation looks like a case now we want to about the spectator and you can see that nitrate mines at the at the beginning of nitrate ions are there and I'm sorry the sodium mindful that the beginning of the sodium ions are there at the end all right so that suspected arise you have nitrate ions here the nitrate ions here so these are all spectators I'm said these items that are not involved in the reaction in as spectator but no less as before we can write the ionic 92 equation and so what you do is you take out the spectator irons and Annette 98 equation is where you have silver combining with chloride to give you the precipitous so this is the net result new combined these 2 solutions this is the net reaction of pain and lastly if you want a ride the general form the reaction he started with silver nitrate and even we write it like this we know it at the soluble salt and Associates completely the right in this form sodium chloride and Associates completely and you end up with a silver chloride plus sodium nitrate and as all of you can see this is not this does not describe sort of the intimate details of what's going on now in some textbooks they call this summer likely equation but I'm reluctant to use that word because you use the word molecular interviewing covalent compounds are we dealing with equal billing compounds here there on a compound self I saw revenues would molecular equation you don't have molecules Sudanese ionic compounds and therefore we will colleges the general form the reaction but it's normal that is an analogy between the and acids and bases that we looked at OK In acid when you acid look at acid-base reactions if you combine acid with the base of the action takes place in an equally was established and you figure out the key to the solution it's alright likewise here we have 2 solutions you combine them together and you end up with an insoluble solids so whenever you take to soluble substances and combined them and you end up with an insoluble substances called that a precipitation reactions are right so a presentation reaction reaction is 1 in which to soluble salts are combined in a quiz solution to produce an insoluble substance or so last time we looked at Assamese reactions and Assamese reactions are called utilization reactions where Pasadena-based react give you Water and very often assault a precipitation reactions other types of reactors will you take to soluble substances and combined them and you should end up with an insoluble substances How do you know whether you would end up with insoluble substances when need pending review to figure out where there the 2 solutions a soluble and when he would end up with something that insoluble you need the solubility rules OK so you already answered these questions you have to have a solubility rules next to you and apply the solubility rules to figure out for the win and up the Pacific did not know the stakes sodium chloride and potassium nitrate Is that of precipitation reactions signed taken sodium chloride sodium chloride is soluble salt I take potassium nitrate potassium is Group 1 metal nitrate has nitrate and alliances that soluble in soluble and insoluble such soluble overtake take these 2 soluble substance and combined them so what what happened solution I have sodium ions chloride ions potassium ions and nitrate and denounce this potassium and chloride give you something that insoluble now because of the solid tells us that it's chloride you have to having the silver led agrees Patasse's ruling metal so when you combine these together would you end up with a precipitous not so that when the precipitation reactions are right when you combine them you have to end up with something that insoluble for it to be a precipitation reactions again now I want to show you a picture of what this looks like itself before we start working a problem knowing all the equations that occur now want to look at the center of this these pictures of him but with your hand out so solicitous this this is the same thing well and we have to be careers and sentiment in the 1st victory of silver nitrate and it shows you the silver irons and 909 now what's missing is the water molecules see that there billions upon billions of water molecules in between these irons but if I were draw those out and it'll be hard for you to see the Catalans amendments so the exact date was solutions and what's missing is just taking out all the water molecules that that actually there surrounding the continents are right now if you look at that this is still trade so what we have here these referred to the silver irons and of course you can see there is the nitrogen entry oxygen as these to to the nitrate and all right over here we have sodium and chloride Natividad turned aside members you take sodium and chloride can to be smaller or bigger can to be smaller so you can see that the smaller circles are in a class quest and this would be the chloride right so now we're taking a soluble salt water soluble salt and were combining them sort you end up with is a precipitate at the bottom and this is silver chloride arrived and these are the spectator alliance which are know 3 miners iniquitous and in a Class quest and you can see that these are silver ions that they are the excess so brands that are left over know how was this out OK so let's count so if each 1 of those represents a mall if I start with silver nitrate you can see I have 1 2 3 4 5 6 7 8 9 moles of nitrates if I have it's a one-to-one ratio survived 9 molds of nitrate this blast which is 1 leader alright and it's 1 meter I know that I have to have 9 malls and this is what so the 1 2 3 4 5 6 7 8 9 so the concentration of nitrate would be 9 molds for the year the concentration of silver will be 9 moles liter if the size of that contains 1 leader on this side you can see I have 1 2 3 4 . 6 0 Williams in 1 2 3 4 5 6 chlorides said this is a one-liter container that means I have 6 most beleaguered chloride and 6 most beleaguered sodium now when they combined remembered mankind equation is 1 another and equations that solar combines with equal right to give missile chloride you will always combined a one-to-one ratio so over here
I have 6 chlorides over here I have 9 silver can so which is Bloomberg In a recent chlorides and limiting because that's the least amount so the 6 chloride combined with common 6 alright right to harmony and left on the other side 3 so you can see this picture the 3 most about 1 2 3 Moulton leader so left over but all the chloride sticking up our right and then you can see that the nitrate suspected rhymes to unite nitrates to begin with and so it was a spectator alliance I have 6 audience I have 6 Williams left always well all right now you have 99 traits can you see that has to be charged balance of United nitrates and only 6 sodium you have 9 miners charges and six-plus charges and you can see the extra 3 Sobers counterbalance the charge are right and therefore you take a charge balance and so this is the excess region and rubber 6 chlorides specific in and out with 6 silver I guess you can see you have 1 1 2 3 4 5 6 chlorides 1 2 3 4 5 6 0 Silver can these combined to form a precipitate that sinks to the bottom of the barrel so you want to visualize what's going on and you figure out that you active and excess amount and a limited amount of this picture kind of describes that OK so now I am ready to solve some problems and the analogy with his is similar to the acid-base titration is only added an acid to a base there was a reaction that took place so you there you added We figured we yesterday that a strong basis for neutralizes taking place the strong base would react with the Wii gasses then you have to figure out how much reacted how much of the week acid is left over and you can figure out key to the solution of the same in here with a look at what is the concentration the 2 reactants we started with political bind them together is going to be a precipitation reactions taking place among the precipitate is formed now will attack when the established equilibrium and forgot solubility and things like that OK now it turns out in precipitation reactions we 1st need to figure out where there is a minimum threshold in other words the precipitation reactions the concentrations of the Catalans and Anaheim's are important alright so in precipitation reactions we need to establish whether sufficient amounts of the Cat Island and are available but for precipitation all right in order to do this we want calculated the reaction caution you guys remember this is the reaction caution but and you learned about this last quarter and so call this QSC and QS be areas the initial concentration before any reaction takes place the initial amounts of silver and chloride so these are the concentrations before these other concentrations before any reaction occurs all right and what we know is if S B is the last then came yesterday then we say no precipitate well that means that there is not enough enough concentration of cabins in and I'm still not sufficient for precipitate to form a cake so that means that initial concentrations of you can find and I are not adequate to form a precipitous on the other hand in West equals kissed all our are if is greater I think history we know that precipitate will form OK so all these will we have to figure out 1st without actually at the reaction occurs to give you a precipitate and when you met that threshold needed for the Catalans and as a minimum requirements to follow precipitate idiot U.S. these great history than your Pacific it will form and you can go on and solve a problem so it's a good example turned to the the worksheet that put on the club's website and let's take a look at this so it really helps to draw
pictures when you solve problems of this type solicitor that's supposed to 500 ml of a solution of calcium chloride with chloride ion concentration of 8 times tend 6 smaller is added to 300 ml of . 0 4 formalist solution of silver nitrate the 1st part is will precipitated silica chloride have formed when equilibrium is reached a case Celestica look at what's what's going on so drawing pictures are really helpful so what we have here is calcium chloride Equus and they tell us that the chloride ion concentration in here it was times 10 to the negative 6 more alert and that we have 0 . 5 0 0 litres so we have 500 ml or we have that's the volume of the solution that we start with over here here they tell us that we have a silver nitrate request and that it was the concentration of silver nitrate now remembers silver nitrate is a soluble salt it's soluble salt and dissociate completely and it had associates completely we know that the silver ion concentration is 0 . 0 0 4 0 0 Moeller and they tell us that their ears 300 millilitres of that solution and now we're going to combine these 2 solutions I rise and the instant you combine these 2 solutions now you even have calcium plus quest even have to see minus quest over here even if silver cannons equals plus found in 0 3 acres and we'll work combining 500 ml with 300 ml so what is the final volume in here now 18 100 ml 10 so what you want to do this fall you start doing any calculations you can see that a volume change the instant combined invisible changed it is a volume change what we know the concentration the going to change our right and so whenever you deal with problems at this time when you think about you want you want to calculate the concentrations of the species the instant you combine them so now we have to go back and recalculate the concentration and here we interested in looking at but the chloride ion concentrations so that initial chloride and concentration should be change the negative 6 of moles per liter sellout this is a typical delusion problem you're actually diluting that solution because combining 2 solutions all right so we know where you will be aware dilution of whenever you deal with a case where the volume changes when you think about what doesn't change the number of walls so you workin read this to the number of malls hardly converged concentration to malls you multiplied by the Constitution times volume In anyone 1 account of the new constitution what you need to do you might otherwise new does MIC that you Kaplan the number of holes because the number of all this is what doesn't change so concentration times volume gives you the number of malls in then divide by the new volume which now gives you the new concentration effect so under the multiplied by the old volume which is . 5 liters in and divide by the new volume you understand the operation and is converting concentration to malls and recalculating the new concentration OK and so on the chloride concentration will come out to be 5 times 10 to the native 6 right now and then and then use silver iron concentration would be . 0 0 4 0 0 miles per liter times the volume that we started with was . 3 leaders of 300 ml new volume would be 800 liters and now that comes out to be 1 . 5 0 times tend to make it 3 most Polito Our right now if you want to you could just keep this in malls Our right or undercounted the concentrations are discounted the new concentration in that last moment you combine them not the volume doesn't change any more you see that I don't have to so I cannot keep everything in concentration and now we have a reaction taking place an unmet reaction is 1 and reaction is silver ions react with chloride ions to give me AGC out right and
so on I remember my 1st question is I have to ask is precipitate going to occur not alright right and how to work together with the Pacific is going to I have to Celtic USB all right and I've actually calculated the new concentrations the instant you combine them so I can say Q S B the walls of the initial concentration of Science times the chloride initial concentration signing to figure out whether these 2 a combined to give me a precipitated are right and so what I need to do is calculated that and my silver and concentration the 1 . 5 0 times 10 3 Muller and my chloride concentrations 5 times tend to native 6 bowlers and Celtic Catholic USB Q sp comes out to be 7 . 5 0 times tend to the negative 9 19 to compare this to K Street and they tell us that the KSB equals 1 . 6 times 10 to the negative tone so which is bigger kids U.S. Q recipes so we know that US B is greater than St and therefore 8 precipitate will form so that the 1st parts so what we need to do is because we're combining 2 solutions and the volume changes we have to take into account the volume change and so on we calculated the new concentrations of the 2 reactants and everything calculus for years and now we know that we met that threshold are we have sufficient amounts of the 2 items so that a precipitate conform now that the president has formed the 2nd part of that question is capped the Cleveland concentrations of silver and chloride ions resulting from the precipitation reactions OK so now we know that precipitated form and therefore we know a reaction is going to take place and we know this reaction will take place so we know that silver irons plus chloride ions will react give you silver chloride so
now we have to do just like we acid-base reactions we have to see what happens in this reaction and we have to figure out which is the limiting reactant which is direct excess reacted and once reacted at the reaction takes place what is left over all right so when you do that it is likely that the acid this problem we look at what we have before any reaction occurs and before any reaction occurs we know that the concentration of
silver is 1 . 5 times 10 to the native 3 Moeller we know the concentration of chloride is 5 times 10 to the negative 6 more alert
Henry and none of the product but we're not interested in products because that doesn't appear in the lot mass action after reaction occurs now I want to look at this and tell me what you think is limiting which is in excess this 1 is limited this is an excess so that limit what is used up completely the excess 1 would be 1 of top 5 times 1 . 5 times in the 93 3 minus 5 times 10 to the native 6 can you see that you take momentous subtract this from there this is the reason that number and therefore if you take the decimals Titus attracted you you can see that it doesn't really make any difference to this number all right because this number is still small compared to that that that approximates to this and this is a limiting and says excess right so we know that once that precipitated wouldn't have 0 amount of fluoride but wouldn't have this left over OK so now they have figured out the concentration of these 2 species now I go to the equilibrium so you see that in all these cases is a reaction taking place in the reaction takes place a precipitate is for now we need to figure out the Bequelin concentration so now we have taken advantage of the equilibrium and so on now wouldn't say if we are going to find out what equilibrium concentrations are in equilibrium that we're looking at is once the precipitate is forms you establish this equilibrium and we know TSP is 1 . 6 times 10 to the negative attention and the initial To begin with and not interested in this solid does not appear In equilibrium expression so I'm not going to look at that but I know at the beginning I have 1 . 5 0 times tend to make it and 0 that to begin with that's what we calculated here are right at the at the beginning we know that this is the excess over that's left over and that's what I'm putting over here now I will look at change because we were not interested in that discipline negative acts site plus X plus X therefore at equilibrium I can say I have 1 . 5 0 per cent and 3 plus tax and a tank so this is what will be equilibrium concentration so now I can say S he "quotation mark trying to locate the he calls them 1 . 6 times 10 the negative 10 which he calls the secular concentration times the chloride concentrations in equilibrium which is 1 . 5 0 times tend to negate 3 plus X times that's all right now ask the seller were still dealing tend to the negative tend to mandate an approximation here yes so I analysts say that my approximation here is that X is going to be really small and excess solar small that compared to 1 . 5 times to the negative 3 this is 1 . 5 times 10 1083 so now I can say 1 . 6 times 10 to negative 10 equals 1 . 5 0 pence tend to native 3 times x and therefore if you solve where X X comes out to be 1 . 1 times 10 to the negatives 7 malls earlier so this is the solubility This is the amount of the solid that actually associated solution are right and if you check validity at this point you should check qualities of this number OK so just to be tents 87 Kent so this number should be so small compared to those that would be neglected and if you check validity it comes out to be . 0 0 7 % and saying all that X is really really small compared to 1 . 5 0 times to 3 and you know that the approximations valid OK not ultimately what they want us to calculate you want us to calculate the equilibrium concentrations of silver and chloride ions are right so now that we know what taxes now we all we have to do is go back and indicate what silver and concentration is remember so well concentration was 1 . 5 0 pence tend to native tree plus X and you can see that equals 1 . 5 0 Tyson donated 3 plus 1 . 1 times 10 to at 7 and you can see
that approximation is valid because it is hardly in this number hardly makes any difference to this number are in December so small that does not change that and invited the chloride concentration chloride ion concentration equals X which is 1 . 1 times 10 to the negative 7 smaller never hear usually the unit because we're talking about concentration and that gives us the concentration of the silver lines and the chloride an instant solution a cake so there is there's an analogy between what we did in for acids and bases where we looked at with combined assets and bases right and instead we combine them with the volume changes so we have to be calculated the amount of each 1 of those in the combined solution didn't react so we have the right reaction that shows the reaction between the 2 of you have to figure out what's limiting and what success all right and the news that account the pH likewise what we do is combined 2 solutions the 1st figure out what precipitates form all right so you calculate center combining 2 solutions in the volume changes you calculated that the new concentrations of the to the incident combine them in if the governor Pacific would form the precedent it will not form you stop there can proceed any further because there is no but if the president does form now you have to set it up and look at the limiting reaction are right you figure out which is the limiting reactant which is the excess reactant and and once you've done that that is that would be you initial concentrations for equilibrium in any way clear expression with appropriate concentrations and then you can figure out how much of each of the 2 canons of that at Caroline and and at bit isn't that everybody itself once again I assigned some problems in the textbooks but also the online homework that is you on Tuesday May 7 also get to practice a lot of that became not during the last 5 minutes what women do is known to want to looking at sort of an analogy were using the word covering the parallels last and when we talk about weak acids we as strong as strong bases after we completed that we looked at ,comma 9 effect :colon effect is the application of leadership these principal right so we're gonna look at ,comma 9 effect and precipitation and it's the same amount of you understand why you should be able to understand the other rights sold and look at common iron effect already or we said it's the application of the shattered principle so we're looking at now precipitation overlooking an insoluble salts with its solubility products sell it might take something like silver chloride and vise establishments equilibrium I know KSB is 1 . 6 times 10 to the native 10 said you take silver chloride and putting up to read curse that forms of precipitation or if you combine the 2 reactants and they reacted you precipitate once you have that if I had a common line that's common to this equilibrium like if I had a soluble salts like sodium chloride so they end up with an plus plus plus minus equals now you can see that what I've done is I've taken a system that's at equilibrium and disturbed that equilibrium by adding I think that is common to that equilibrium so what is in my eyes disturbance of stress I've added to which chloride are right and that it too much chloride houses system in response it's going to shift was left on the right to it's the left and so it's gonna shift this way to consumers the added extra chloride and then the system will ultimately go back to equilibrium and we call it was established what we will see is because the reaction ships this way to establish an equilibrium we know that's solubility decreases all right so the net result is that if you take the ,comma 9 effect and you had a common eye and then what happens is that substance becomes even more insoluble all right and so are solubility decreases so I want to ask you whether you could try this problem at home because it's very similar and then at the beginning of class next time will take a look at this and this is very similar to that is the common effects that we live have in the weak acids and bases solicitor what's going on here we have still chloride and sodium chloride so now we have substances and is a common I'm just chloride and you take silver chloride and . 1 Waller of ACL what is its solubility OK so can you
guys do that as homework and be a class or with this problem again and was shelved we will look at how the solubility changes right so we'll stop there for today


  734 ms - page object


AV-Portal 3.9.1 (0da88e96ae8dbbf323d1005dc12c7aa41dfc5a31)