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Lecture 13. Aqueous Equilibria Pt. 2.

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Lecture 13. Aqueous Equilibria Pt. 2.
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UCI Chem 1C General Chemistry (Spring 2013) Lec 13. General Chemistry -- Aqueous Equilibria -- Part 2 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: 0:03:25 Weak Base vs. Strong Acid Example 0:07:04 pH Titration Curve Picture 0:12:10 Understanding Strong Acid Neutralizing Weak Base 0:14:33 Solubility Product 0:22:24 "Insoluble" Salts 0:26:26 Introducing Ksp 0:35:50 Rules ofr Solubility in Water 0:41:14 Solubility and Ksp
Index type areas Säuren grade concentration basic titration case Pigmentdispergierender Faktor
species Digoxigenin chloride Salzsäure titration case man Ammonium Neutralisation molecule Magnetometer conjugate Kompetenz <Bakteriologie> period fall Harmful Ammoniumchlorid Eau de Cologne association concentration balance asset steps Darmstadtium proton chemische Reaktion solutions buffer water van Säuren Iron salts basic form den ammonia calculations
homogeneity elastic modulus Agate Bohr chloride Memorial cluster molecule Löslichkeit Medroxyprogesterone period Soluble Salts crystal form fall concentration Gases Topic Katalase chemische Reaktion solutions end firm law of mass action Säuren clusterization compounds Granule (cell biology) form calculations precipitation sodium hydride species Weak NaCl plant titration case man Common Magma parents mixture Ideal conjugate reactor type deposition man water Silver chloride agricultural Computer animation Iron salts basic AdoMet
precipitation NaCl chloride Memorial case man Alfred cake temperatures overexpression active site Ideal Mars Löslichkeit Soluble Salts silver phase Arginine association concentration balance tuberculosis solutions ash Californium law of mass action water Silver chloride systems model salts basic History
metals power transition metal balance concentration aluminium Ethylen-Vinylacetat-Copolymere case charge OH- man Alfred Computer animation meso cell Mars Löslichkeit Soluble Salts
Insulinkomabehandlung Sulfate Bohr Aspartate transaminase chloride Thrombospondin set sulphur Mast cell Potassium enzymes cake Exon barium Mars Löslichkeit Soluble Salts Calcium Notch signaling pathway association concentration Kaliumacetat Strontium solutions end Rübenmelasse law of mass action Lava van Säuren Optische Untersuchungen Gamma compounds Lymphangiomyomatosis form Acetal antigenic bond Polyurethane Weak Calcium sulfate Calcium fluoride Essigsäure case man Nitration Ammonium fluoride Quecksilber Nitrate Magnetometer Calcium chloride tool Zigarre conjugate mineralischer silver reactor metals areas agar Bromide Electronegativity water Silver chloride Natrium Combining Eisfläche Ammonium Computer animation initial function Iron salts basic atom AdoMet ammonia
Calcium Index power Polyurethane concentration Bohr Calcium fluoride case fluoride Computer animation Meeting/Interview Calcium chloride Gamma Iron Löslichkeit form rate period calculations
a quick announcement I wanted to remind you that yesterday you would have received a PDF file your grade exams so take a look at the example and if you have any questions about the grading you should print out the entire exams and take it to you with a view to discussion arrived and talk to you hear about it you don't think there is an error in which you need to do is to print out a copy of the exam attach a note explaining to me but the problem areas and you need to hand it to me not the Chileans are right it's all really grades have to be turned into me please do not send e-mail because as you know it's a class of this size it is the icon of the 1980 Wikipedia files it's difficult for me to keep track of sent was so that's why I'm asking you to print it out attach a note and then turn it into me and the deadline is 2 weeks from yesterday because it's 2 weeks from the date when you was saying the PDF files for me OK and so within that deadline you turn it on and then we will take a look at it again presented everybody's so please do not send me an e-mail are you can hand it to me after class will begin handed to me before classes begin handed to me on after my office hours and if I'm not there you can't even slightly and my daughter of cases as long as I get it within the two-week deadline is that clear everybody OK so you don't remember we're looking at acid-base titration is and we said we will look at 3 types of acid-base titration strong acid strong base of bicyclists and we looked at we acid strongly now will look at that scenario where you have to be made was a strong acid so look at the titration you can see that the legal base is placed in the real-life last and that is typically in an analysis of that is the 1 that has the unknown concentration would place the strong acid in your rat and when you start
the titration now with look at that what the reaction would be remember Reeves said that if you have an accident base we can coexist large amounts of acids and bases do not coexist they will react to give you water and salt OK so let's see what happens here simply write the complete reminded equation and then I will start with a strong acid as strong as we know dissociate completely sane reality when it dissolved in water you have enjoyed your mind and chloride ions so that's a strong acid now we have the week basis we know we may serve as do not dissociate did not react to water there they tend to be I'm dissociated all right or in this case they would not think of a proton because it's a week basically know that whenever we see the would week it means its preference is to remain the way he did OK so this is what we have at the start now we're going to let it go to products now this is the basis of the acid
we know they're going to react to give me NH 4 plus requests plus water class CEO minus Our right and so what you end up with ministers strong acid and the weak base will give you its conjugate acid when water vapor and if you look at chloride ions and there at the beginning of chloride ions are there the and so the chloride ions are spectator iron so we only 1 spectator I'm here which is the chloride ions the the right and that and equations now we take away the suspected Ryan so because remember the expected rise to participate in the reaction that just there and survivor the net and equation when I end up with is Jounieh mine 1st ammonia which is the assets and the base will react to give me Water in each for Plus which is the conjugate assays and what all right so far this is the acid and this is the basis of the acid will donate a proton to the base of the unit for class and water so this is the neutralization right and and so on it will look at them as in all of this reacted completely when they're at the clueless .period understood geometry .period you have is water water is neutral plus you have in each fall class so melodramatic for plus additional class is the conjugated acid of a weak base which is in its 3 so the dig in its 4 plus would you expect it to be acidic basic on neutral the city Orange so we know that the equivalence pointing out that it has to be a city right and then if you right the comfort of the overall reaction or the general form of the reaction what it will be but where you have 8 Seattle which is a strong acid reacted with ammonia which is the weak base giving you In 84 for but in fact I'm writing general from the reactants editors turned out to be giving assault here write to you right in the general form you see there were 2 forming is ammonium chloride performing the Sox strong acid reacts soaking everything that the general form the overall reaction or sometimes they call this the molecular equations are way identifies the molecules hippies equivalent competency can use would molecular right and is also called the molecular equation a tonight so that what the pH titration curves looks like so this is what the titration currently looks like so Over here we're measuring pH on this side of the Y is we have the pH of the candlelight but we're here we have the volume of the strong acid that's bad and you can see now the shape of this is very different OK to begin with you just haven't we base our right before we had any strong acid we have only a week Mason the flat so we expect appeared to be Hi right is it's a basic solution now as you add a strong acid in your neutralizing the weak base and converting it to each fall class which is a weak acid you know the pH is going to go down I think so what we see that the pH decreases but in this region and this is the buffer region are once again over here in this region here it would act as a buffer so that's why it flattens out as the the pH doesn't change dramatically they're just kind of flattens out and plateaus because now what we have is and that makes that solution would have been each 3 which is the weak base even at any each for Plus which is its conjugate acid and you mixtures of bolt In substantial amounts and saying that we did can act as a buffer all right so that's where this flattens out and then as you add more more acid Nigel Moffett and complete walk and everything is going to be converted to an 4 plus so at the equivalent .period now you can see all I have is manageable plus seal minus and Water Seal minus is the conjugate base of a strong acid we know that's neutral to seal minuses neutral water is neutral are right and therefore the only other species you have injuries in its for plus in the initial plus is the conjugal passage of a bill based it's going to be acidic and therefore the pH is less than 7 all right so you can see that the pH is less than 7 OK Beyond this point now just woke with a strong acids so beyond coolants .period appear just as determined by the extra hydrochloric acid that's their which associates completely new to the young lady who was .period now rapidly the solution gets the acidic all right now if this is the equivalent .period so you can see that in this titration on the concentration of the different OK in this titration it turns out that the cause .period that 15 million I write so have equivalent .period would be 25 said he did 25 ml that correspond to that and so at 25 ml we know that we have about where there where the concentrations of the week get based and the weak acid equal to each other to the concentration equal to each other you know it's a buffer in the concentrations equal to each other the ratio of assets to base would be 1 a lot 1 would be way 0 and therefore we know pH equals all right so here and even that we have a big in solution and this gives me the point at which pH equals contained Our it's not critical PKB even know we have an acid down there some students white we haven't and we have a base down there so why aren't we talking about here they were thinking remember pH always equals picking according to Henderson has about equation for the concentrations of acid and based of the same alright so here this would be pH the aid and so on Is that your amendment to any calculations and I ask you what is the pH half the cost .period and just look at this table and you look for the conjugal acid-base there that we're interested in looking at and that would be ammonium ammonia and ending up with his 9 . 2 5 sells watches this pH
correspond to 9 . 2 5 I because we know that have the coolest pointed the key testicle game Is that is I couldn't really so now we've looked at all 3 types of titration so I did not do any calculations here but you should be able to do the same type of calculations that we did the week assistive strong or strong acids strong base and I'd like you try that at home in fact signed a problem from the textbook where you get to practice that do just go with the plane so her her question was what happens at the close .period can be sold you have to turn it into the net find equation so this titration what's happening is the strong acid neutralizes this the week base all right and so censor what happens is when his reaction takes place you have need for plants and water being for OK so when you have stood geometric amounts of or equivalent amounts of all where all of this react completely with this and all of this reactor completely with them so that you have no access reagent leftover arrival both reactants react completely and that happens only equivalence .period because you have to have stood geometric amounted to have that the right amount of each so that you don't have any limiting reagent you don't have any excess region they react installed cameras come out so that only happens at the equivalence .period Kato said Boquillas .period when bolted the reactants to react completely all that you have been left behind is just the product you don't have any excess region left over said because all of them have all that you have this just in each fall plus what and seal minus irate perspective Irish CEO minus still minus is the conjugate base of a strong acid and we know but that's we know what it is neutral a right and so now returned image for plus solos loading 3 species in solution to gender-neutral plus you know that that of the gasses it's the conjugate acid week babies and therefore two-week gas it's a weak acid it's going to be considered right and therefore the pH should be less than 7 that OK so no 1 will complete looking at possibly titration and now we're actually rated to 1 of the last topic that wouldn't look at in terms of titration so by now you buy the expert at solving equilibrium problem and we've focused this entire quarter was focused on what date was equilibrium what happens in water are right and that's kind of has been the focus all along that we know that the last type of equilibrium and this deals with solid ability rise so will look at solubility promise "quotation mark and as all of you the solubility deals with friends when a substance that is also when looking at the close of a really solid with the product in solutions and so the words solubility is related to soluble when something is lost all right so let's take something as all of you know we know that many many ionic compounds dissolve easily in water and we call them soluble salts inviting soluble salts so will start by looking at soluble salts and all of you know when we use the word Salsman talking about ionic compounds and we said If you take iron compounds that are soluble what happens the institute dissolved in water what happens to soluble salts is all and when it is all what does that tell you they disassociate completely OK to give me an example of a really good soluble salt Inacio we all know table salt in a Seattle it is a very good soluble salt so I start with ended all Latino that if I take a beaker In end solid sodium chloride C take all of you know that and kind compounds tend to be crystalline solids and you take common table salt you can see that they have nice Christa line granules and said you take a spoonful of that and put it in the cold water and stir it what's going to happen it dissolves completely and we say dissolves completely we know that it has dissociated completely to give you any A-plus and seal again no 1 wanted to examine and others from fold and stirred up it's going to dissolve Martinez spoonful and stir up the result I can keep doing this until the point comes when that solution is completely saturated sodium chloride society putting more and more and more sodium chloride and what I'll end up where it was really saturated solutions at the which this gets to be saturated we know it's saturated because you can't take it anymore if you add another spoonful of sodium chloride it's not that it is all the more because that solution has taken as much as it can take and therefore what will happen is have unresolved sodium chloride at the bottom of that we're talking about is saturated solution a solution that can take as much sodium chloride as it can take and now it's beyond the point where you can dissolve any more sodium chloride at that point you'll have a solid material at the bottom right now when you have a solid material the bottom what happens is that you will establish an equilibrium where you have indeed plus speak was 1st In other words you will establish an equilibrium where went 1 unit of see how it is also 1 can and I dissolves somewhere else they will deposit money unit will deposit you see them so if the solution is saturated then what happens is you establish equilibrium where you have a solid material dissolving and you'll have it decided to dissolve any point given have to dissociated Karadzic and associating with each other and deposited on top of that solid OK and sometimes the solid material the bottom is called we call this a precipitate so when you have 1 dissolved material the bottom we say we have a precipitated the body a case now since this isn't a call of
a we should be able to apply the law of mass action to this scenario but it turns out we can't because this solution is not ideal this solution is not idea are right and the reason it's not an ideal is the solution is not an ideal because it it was not homogeneous and the reason it's not homogeneous is that when the solution is saturated the saturated solution but has mixture is finally hairs can iron clusters all right so the reason that the solution is not an ideal it is because because it's so saturated now the cat Kansas so crowded by chance there is just so close to each other that they appear to be common I'm here so when the solution is so crowded with Qatar International now In solution you have 1 can and I'm so close to each other that pair up and you have an Olympia or by pure chance if for them together 2 pairs of Qatar and demand will form a cluster you can have to 3 here is a calendar and forming at 3 close you can therefore pairs forming of clustered so what happens is now you have all these different species in there you just don't have cash in hand and separated from each other on top of that you have appeared paired up :colon on repair it can have a few can forming clusters and the number of talented man in the cluster conveyors so the net result is now you have mixtures of of different kinds of parents and so we say the solution is not an ideal give your solution has to be uniform is solution if you don't count the concentrations 1 determines how much of each species is there you have mixtures of all this you can have an independent separate continents you can happen that solution not only that but you can appear the lines are right just 1 pair or you can have 2 3 4 5 hitters alliance clustered together and as a result the solution is no longer homogeneous alright and because not homogeneous Reseda non-violent solutions it's not an ideal solution is where everything is homogeneous dissolve completely and all the species of the same self ideal solution would be just having glass-and-steel minus and that's that they deal clusters and appears and so on now becomes non ideal so the net result is the law of mass action cannot be applied right so we take assault that dissolves easily in water soluble salts you Yukon solving equilibria problem you can use the lot mass action because that solution it is not ideal but you take insoluble so when call insoluble it's also OK all we call them marginally soluble salsa write something completely soluble salts marginally soluble salts arms there's another that we use in our and slightly soluble salts of insoluble salts marginally soluble salts or are like soluble salts all right now to take the they all mean the same thing so we sometimes use the wedding soluble sometimes use would marginally soluble sometimes used that with slightly soluble so these are the exact reverse the soluble salts soluble salts are the ones that is all completely OK everything else falls into this category and an example of that would be something while silver chloride case chloride is a precipitate it's insoluble and the reason it's insoluble is if you place it in what it just seems to the bottom just forms of precipitating so Net we don't need to form a saturated solution instead to put silver chloride down here it will form a solid it'll farm a precipitate and because the insoluble modulus Ollila slightly soluble and tiny tiny tiny amount actually dissociate so it's like this is the equivalent of like the gas memory gasses we bases dissociate only a small amount of the majority of its status on dissociated the same thing here so when you take an insoluble Marjorie soluble a partially soluble solved now you set out this equilibrium now and then is an ideal solution why it's not saturated this is a solution where only a very small amount of the silver chloride dissolved so solution far apart from each other and so there is no chance that you can phone line appears on clusters of care because the amount is so small and they're separated by billions and billions of water molecules that they don't I right in all online pairs on clusters and so what you do is you established equilibrium where some solid will dissolve and and some of the dissolved material combined to give you a solid and you would establish an equilibrium and because this is an ideal solution and we can apply the law mass action right so since this is an ideal solution the launch of mass action of above can be applied right to know only in the case of insoluble all marginally soluble are slightly soluble substances we can apply the law of mass action and begin right out of a of title of mass action then we can write the equilibrium of and look at it which is the
solid precipitated in equilibrium with disassociated silver linings and chloride ions the OK noted there is the difference between soluble salts and insoluble salts are the attracted water soluble salts and you put them in water dissociated Yukon Anaheim's because they're attraction for water is greater than the attraction of each other insoluble models soluble salts the attraction for each other is much greater than the attraction for water and that's why we follow at a precipitate don't associate water the grandest Associated as solid became so if you look at silver chloride now we can write this is an equilibrium between that disappointments different from the other columns we looked that because we have a solid and we had the other is dissolving it was solution when you have 2 different phases in what we call them I had to do this and do what best remembered last quarter when we looked at the basic fundamental concepts of equilibrium when you deal with PetroChina systems that have fewer solids pure liquid what we do we don't include that in the long grass section of equilibrium expression so in this case if I were to rise to the equilibrium an expression which is the lot mass action with sticky key and assess the special names so we call became equals the silver and concentration times the chloride concentration and this has a special
name this is called the solubility products constant and amendment that would solubility is the amount that is also a writer and so you can see product means time so what we're looking at is the solubility of silver chloride amounts of silver and chloride that is all in your multiplying that and that's what gives you the solubility products sees this is the solubility of 80 plus is the solubility of chloride is the product of that and therefore we call it the soluble proper constant because these are all substances that don't dissolve easily in would you expect history to be a big number or a small number of small because the court relies entirely on the solid site only very very minuscule amounts actually would dissociate so all the values are really really small many of the kids value is lot to be like sodium chloride I write give case really loud then we can apply kissed 2 soluble substances because solutions and on ideal are right so we don't apply Casey to soluble salts really applied them to insoluble marginally soluble was slightly soluble so if you look at the value for their best this is about 1 . 6 times 10 to the negative attention if you were right the unit but as you can see this is multiple leader is to be most beleaguered Soviet mole square meters square cake often we hate it even tho we know all that equipment constant has unit very often we admit that unit so you should remember that if it had earlier that this was the most square meter square cake and this would be at room temperature right now the violent ways memories said that the equilibrium constant always depends on temperature so change the temperature the value of this would change and said by raising the temperature to 100 degrees Celsius now this value would be 2 . 2 times tend to make debate now look at that and tell me now there's a clear you raise the temperature the scarcity increase decrease Increases Remember what is clear is Italian its solubility product tells you what the solubility its size you raise the temperature what happens to solubility it increases that means more dissolves and we know that you wanted the substance you increase the solidly would you do to heat up our right and you can see when you heat up and increase the temperature case the actually goes out and gives the goes up it tells us that the solubility has increased OK now if you want to know about so let's take some of the examples so it might take another example would be PBI to this is an insoluble substance that equilibrium you would set up would be PB 2 plus quest us to my mind as requested to items there so if you look at this and Associates is going to be to find minus remember it all of these equations you have to maintain charged balancing consumers start with something that's electrically neutral therefore this site has electrically neutral as well led police to last and therefore it's going to have to I'm to balance that in all wrote 2 plus 2 minus the balance each other and if you take the case before this this is of the order of 7 . 1 times 10 to the negative 9 if you take something like and so did I wanted write their lot mass action for this this would be the concentration of PB 2 plus times the concentration of I
take the power to if you take something like aluminum hydroxide this is also insoluble substances the equilibrium you would establish is now in the wake of the charge balance is to look at hydroxide What is a child and hydroxide minus 1 how many hydroxide either 3 so that injecting minuses to counterbalance that charged him with 1 aluminum so much of the charge of aluminum come out to be 3 plus are a cell you have to figure out what the charges in every case you have to figure out what the charges you can find and what the charge the Anaheim is now usually who won medals you know have a charge of what plus 1 1 is a charge moved to metals quest to the transition metals away variable changes into the transition metals you don't know what it is and you want to figure out who always turned to the and I said You know the charge the online you can forgo the charge can so this case aluminum comes out to the street lust and hydroxide you need to be hydroxide to balance that charge a right and if you look at his feet case that comes out to be 2 times 10 to the negative appeared to that something is tremendous small numbers you still very tiny amount of that actually is soluble of the solubility is really really small and so on if you want right kiss before that kiss the would be in the concentration of the aluminum catamarans times the concentration of the hydroxide taking the power 3 so because pierced deals with substances that are insoluble we know that all pierced the values have to be really small you can never have increased the number that is greater than 1 hour because that the soluble salt and you can have accused the Solomon was sort of so here it but I pulled it out of the handled really was small and that's OK because whatever they wanted you to focus on it that just like we have tables for k values the tables that case the values and uses these are in alphabetical order are right and so you can see aluminum hydroxide and you can see the case that corresponds to that of what I want you to take a look at it take a look at all that he the values Connecticut you see that all of these are numbers that are less than 1 because they're all insoluble marginally soluble are slightly soluble and they're all going to have really really small numbers that are so that's important to remember another thing that I want to do remember it as that 1 way for you to identify with the substance is insoluble all soluble is living as a kid value that's really really small it has accused the value at all it has to be insoluble Marjorie soluble was slightly soluble another way to figure out where there substance assault is soluble
or not is to look at the solubility rules
it in high school you have seen this before and recalled is the solubility rules and this is the guy in the year to figure out whether an ionic compounds of salt will dissolve in water and sewer another way for you rather than looking at his values and not way to figure out whether an ionic compounds salt is soluble or insoluble monthly Sybase slightly soluble is to follow these rules now I don't want to memorize these rules but I really don't want to be able To understand his rules and if you have the will to right next to you the able to apply them alright so on and examine them I want to be used as I like to provide the rules I'm more interested in whether you can actually apply the rules rather than whether you are good at memorizing the rules player so the 1st rule is that all nitrates and acetate are soluble so if you don't mind a compound where the end the nitrate or the is an acid it's a sodium acetate potassium acetate all of these will dissolve completely so the 1st is that nitrate mining compounds with enzymes that are nitrates or acetate are soluble in water sometimes right that all of the lasted like that sometimes derided as CH 3 C O 2 miners there the same thing OK CH 3 0 to minus is 1 of the conjugate issue of the week the gasses so ascertained is the conjugate base of the weak acid acetic acid became the 2nd rule deals with "quotation mark bromides and I'd like to what we know is all rights of soluble except when they can find a silver in the Carolinas mercury in the Qatar News led all right so except for those of all chloride soluble the same rule applies for bromides and the same rule applies either right now the 3rd rule is also sulfates soluble cigar and I was assault they also offered to soluble except barium strontium and lead a case here all insoluble then they say calcium mercury and silver not only slightly soluble remember for all intents and purposes as well as saying that insoluble mean the same thing as slightly soluble mean the same thing as marginal soluble it's like categorize them all as we all right you the week after the strong acids in this case there either because all completely which of the soluble salts or the opposite attended yesterday that the title case thanks for pointing that out right it's calcium sulfate appears so that software there are 2 S's there in New Cross of the located at sea OK so himself consolidated in America itself mercurial sulfate and software are only slightly solid but that 1 is all 1 middle irons and ammonia lines soluble right said you have sodium potassium or video can ammonium their soluble in water all hydroxide the insoluble who won the alliance and ammonia minds barium strontium touts invisible to metals by barium strontium calcium are marginally side that that this set of rules of the class websites can printed out right so I put it in if you look at yesterday's date I put this up already singing comprise about 6 is also hides soluble acceptable when airlines and ammonium calcium and demands in the area mines are also insoluble all lost faith and college the insoluble except who won the lines mines was schoolmates are only slightly soluble except those who won that alliance among might obtain so what are you need so this covers almost every and I don't have any combination that you can come across all right now what I want to keep in mind is that there are some very rare instances where you may have to rules that give you kind of it's very rare that tools will debut opposite information all right if that happens then what you have to make reading mind anymore on top has precedence over any rule at the bottom is a clear so kind of goes in that order and you encounter it's very direct very unlikely opening Canada but you ever encounter where tools can you conflicting information then always make sure that it on top takes precedence over anything below got it so you know you can use kids the values or you can use soluble the rules to figure out whether it's solved is soluble 1 notch again send them home we didn't know that we understand the difference between soluble salts and insoluble salts and that's why we focus only on the insoluble where the marginal insoluble or the slight insoluble compounds now agreed to look at solubility and TSP our right to wanna look at the relationship between solubility and Keasbey we said before it became gets bigger or any substance that has a clear sky that has a big numbers we now that's related solubility so that these exceptions will be dissolving a little bit more then something that has a lower case obtained the solubility refers to the amount of the substance that dissolves so everyone to look at solubility and let's take an example of of silver chloride so we know silver chloride this associates to give you silver can irons and chloride and signs and we know this equipment is given by Kia speech and including constant is a relatively small
number that 1 cannot what is the solubility and how much of this actually dissolves right To do that we don't need to go to the complete ice because you look at usually use the ice chart when you look at the initial than the change in an equilibrium if you need additional concentration now you look at it to what my interest in the initial concentrations of accord is isn't dissolved in water anywhere are doesn't appear in the lot of mass action so all I'm interested in looking at is what I have and equilibrium candidacy at equilibrium divide Look at the concentrations we know that a negative effects associates we know plus plus form said equipment all I'm left with is just that X X you never see them so all I'm interested in is the amount of silver chloride and equilibrium and since they associated in a one-to-one stood geometry that can be accessed are right so I know that he has been equals 1 . 6 times 10 which gives me the silver and concentration times the chloride and concentration which is at times X which is at square cake so badly the square root of that I'd end up with 1 . 3 times 10 to the negative flies moles per liter now there is the amount that is all dissolved member this is the amount that's consumed with his native X amount that's only since this is a malls we call this solubility all right or in general solubility and this give the amount of concentration of the AGC that dissolved right member solubility is related to how much actually dissolves how much is soluble and therefore it when you talk about solubility it gives us but in terms of concentration the amount of the starting material that does all of the which is X now sometimes it's customary To give this as GM solubility the city wanted this in terms of grandfather sell here this is more solubility and even smaller solubility the unit is malls for leader all right if you give any in GM solubility wanna know how many grams of the solid material actually dissolved our rights and so if I want to convert the Bulls to GM were going to do the 2 multiplied by the mall amassed right so I stopped 1 . 3 times then 5 moles per liter and multiplied by the mall a massive silver chloride C you go look at the molasses silver the mall massive chloride added together that gives me 143 . 3 grams of silver chloride prayer more so this is the mall amassed this is times the mall mask of EGC which is the reactor because solubility refers to the amount of the reactor and dissolved a case so you can see molds and also cancel out and so I end up with 1 . 9 times 10 To the negative 3 grams per CIA so far UK calculates solubility in terms of concentration and that is x that's the amount that dissolved that the more the solubility or you can calculate in terms of GM and that would be GM solubility on-site grants for the guests or sell the unit would be grams per liter diagrams from all reasonable amounts that are so let's apply this up In a problem so let's take a very straightforward and easy problems and so if we take this example where the solubility product constant for calcium fluoride is given to you can calculate the concentrations of calcium and fluoride in a saturated solution of calcium chloride at 25 degrees Celsius and determine the solubility of calcium fluoride in grams per liter now fear they using the word saturated and when you talk about insoluble substances saturated refers to adjust the teeny tiny amount that will dissolve right we doubt about soluble salts used with saturated it means that it's super supersaturated together so that's the difference so you should be able to recognize from the kiss the that's tend to make 11 and so this is an insoluble substances of very little actually dissolves and when when the maximum amount that can dissolve is dissolved we call that a saturated solution but the maximum amount that insoluble solids dissolved is going the way a minuscule amount that is so looking accounts fluoride solution the equilibrium so we know this is insoluble and really the so this year the clarinet in establishing the best customers grew to 6 got have 2 plus fluoride is Group 7 it's that have minus charge there 2 of those and we know kissed the Wallstreet . 9 times tend to native Levin that numbers have been William was small that means that if I want a calculated I noticed the there might have been the concentration of calcium and Florence I know at equilibrium it is consumed how much calcium form that's but
indexes consumed how much fluoride form 2 x 4 cases don't forget that and therefore we know that equals calcium iron concentration times Florida and concentration raised the power to which his x times 2 x squared our right to make sure you put this when apprentices because of you take 2 x squared that becomes forex squared times excellent that for excuse so we know that X amount for next cue sorry for its execute future equaled 3 . 9 times to native 11 which is his speech therefore he worked out the the value of X he comes out to be 2 . 1 times 10 to the negative for mortals square leader so at the solubility this is Moeller solubility this is the amount of solid and that is all OK the 1st part is they want to capital the councilman concentration so therefore the calcium iron concentration is actually acts and that would be 2 . 1 times 10 the negative for Wall if you take the fluoride and concentrations of fluoride concentration would be 1 2 acts and therefore it should be 4 . 2 times 10 to the negative for for more now lastly they wanted to calculate the solubility of calcium fluoride in grams per liter to now we want to calculate GM solubility and that would be the mall solubility which is 2 . 1 times 10 84 for most beleaguered times the mall a massive counts in Florida saluted the parent-child calculated the mall a massive calcium plus 2 fluorides energy and the number comes out to be 78 . 1 grams per mall malls of malls cancel and this is a calcium fluoride case and therefore but you end up with it is 0 . 0 1 6 grams per liter of calcium fluoride so the grand solubility and gives you the mass of calcium chloride actually dissolved when the case and that we figured out game
itself next class for the sake of you more examples of solving equilibrium problems associated with fiercely alright .period therefore today