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Solutions: Solubility Curves

Added Apr 06, 2016 •

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hey guys this is Mister posted on today's video will be checking outside the curves it's a way for us to express have temperature affect solubility but the actually put it on the graph so we're going to be get on temperature today and its effects on how things dissolve and will be expressing or information on a curve which is kind of a graph let's get to it before we get into this whole entire top would do want to go over a couple key terms the first key turn want to get into his saturation what is so what do you say what does it mean when something is saturated if it describes a solution that has the maximum amount of solute dissolved in max amount of solute that has been dissolved a good analogy for this would be like a paper towel that is soaking wet the paper towel can no longer absorb any more water therefore it's saturated with water another way to think of it as you're making like an iced tea mix and you're adding like iced tea to a glass of water the point at which no longer will no longer dissolves and actress starts to accumulate turn the bottom of the glass that is the point at which the solution is saturated not reverse on the other side you're going to see a solution that is unsaturated that's the point at which you can actually could need to dissolve more of that substance you have not reached the maximum dissolving Point yet making that iced tea a good way to look at it would be to say I can continue need to dissolve more sugar into my iced tea mix you know what your solution is not saturated yet you are unsaturated another examples of paper towels if you have a paper towel is dry it is totally unsaturated meaning you have a lot less than the maximum amount of water that that paper towel can you know a paper towel that is dead or even sort of wet it is not 100% saturated  hello if you can still absorb some more water you're probably without is supersaturated and that's not true crazy I got a hold back we're not going to go nuts in this one but written the stupid ascribe a solution that has more then a saturated solution has your dissolve more solute than you really should at that given temperature okay solution  this is a solubility curve and has three regions and it has those terms who just defined the key thing you're in a sea of mine is this graph okay to this line that goes right down this crap this is the curve looking for a solubility curve this is a curved line and that's my side leg the line represents the point of a temperature and solute that is a saturated solution Waypoint on this line are the conditions for a solution to be saturated check out the accys here on the x-axis you have temperature for dealing with temperature today over here saw you is how much of a substance dissolves  so once again this curve is nothing more than points that's at this given temperature how saw you can I dissolve and you go over this line over here at this given temperature right here and we go up to this line or here okay this point I can dissolve this much in that solution is an unsaturated solution what is this point right here that given temperature and that given amount of solute dissolved that would be an unsaturated ocean the whole Zone above our curve let's just say I pick this point right here was that temperature going down there I can dissolve that much if my solution has who's conditions it would be a supersaturated condition in likewise if I have any point on this line here  they would be considered matrid Solutions  here's a good example I found this picture on the internet I thought I was a pretty cool picture sugar sugar in cold and hot water and cold water  there is this much sugar leftover the bottom of a graduated cylinder and you can see 35 liters of water if it were is hot I have roughly 5 milliliters sugar left so what is it saying is that well I have a 10 milliliter pile up of sugar over here and I have a 5 milliliter pile up or sugar the point is when the solvent is Hot Sugar can dissolve a lot more  okay so hot would be considered what 100 degrees 80 degrees add the point is this if you track this a degree line up at what point does it become saturated the solution is saturated 4/8 degrees when I hit this line how much of my sugar can I dissolve in their let's go over this way and find out I can dissolve roughly recorder 360 misses grams of solute so if I had a degree water I can rough it is off 300 Lacey grams of sugar in 100ml of water that's pretty cool how about this what if I have 20 degrees water how much sugar can is off what colder water holds less saw you ever find out how much that's going roughly 200 g so check out the conditions here can dissolve 200g and 80 degree water can dissolve roughly 360 just driving home the point that were making year is that the warmer the solvent the more in this case sugar I can dissolve but that is not true for every single compound great example is going to be soft I do lines appear in 15 minutes to see that roughly cold or hot I have the turn out of solute in this case soft  that is remaining let has not been dissolved yet and so what's that is I guess that it really doesn't matter if it is hot or if it is cold salt will only dissolve a little bit more in hot water is it really cold water and therefore very mine is it called a solubility curve the curve is right here the curve for salt is very very flat it doesn't change as drastically as sugar is that all substances will have solubility curves  most of them increase with hot solving this case hot water but I'm also will go opposite some of them will increase in cold water it will shine example that act application question SCI buddy curve the question is what temperature would a solution need to be to dissolve 110 kg of solute just saw you just miss curve over here on access accessibility kilograms per 100 kilograms of water so if I wanted to solve 110 kg of Saw how to sculpt airwair 110 is that's 100 120 110 is probably right there I'm just going to follow this over until it hits the saturation Line This the point at which solution is saturated and now I'm going to go downwards and find out what temperature I would need and I would need as you can see a 60-degree solvent So What temperature would a solution need to dissolve be 110 kilograms of solute I would need 60. solutions kind of what we can use to care for is one way to find out how warm a solvent needs to be in order to dissolve a give amount of solute that was the next question  if a solution had a 100 kg of solute Set an appoint off at 100 kg of solute in this one tells me that I have 80 degrees Celsius and the question is is that solution under those conditions of 180 is that saturated will find out saturated has to fall directly on that line so check this out I'm going to draw a line going upward  straight up words and I'm going to draw a line going over this way for the hundred and wherever they cross that is the condition of my saw that my solvent is 8 degrees in temperature and amount of solute I have in there is 100 G weight out on a scale and any play that is below this curve represents an unsaturated solution so the question is is it a saturated solution no it's not saturated is actually I still have more to go still technically dissolve  that much more which is roughly be I can do still dissolve roughly what's called that 25 grams more or 25 kg more solute in that solution example of a very common side Lee curve you know that you would see in a textbook where they're going to reference many you know different compounds in order to express about the side door is not even two compounds that are roughly have clothes or similar solubility curves they're all very different have one of the very tough you have to realize there's potassium iodide up here you know we have ammonium right down here we have sea to SFO going over this way there is any how many cells in the previous light a very Broad and flat Curve will there you see it right there still very bright enough left the question is which solute which one of these compounds is sidewalk at 10° C compound compound that is most soluble right here is going to be potassium iodide cuz at 10 degrees Celsius I can dissolve roughly I'd say a hundred 136 grams of it in 100 G of water so that would be the most oil also ask what is the least Seibel substance at 10 degrees Celsius and you to find the lowest you no charge here there's a curve right here that belongs to two chloride Casey little three  I do want to bring your attention actually to two compounds that iconic say go in the opposite direction and it's play The Curve goes down in this direction meaning in 0 degrees Celsius it is more soluble than it is at 100 and the same thing with Cesar sulfate right here it is more soluble at 0 degrees Celsius than it is at 100 Celsius so not every compound increases inside body as the temperature increases although allowed them to most than probably do some of them do not check out this question guys how much KCl can be dissolved in 90° solve it so it's fine the NaCl line this line are here is an ACL  and 9 degrees and you go up and said the most I can possibly is off is that put right there I'm going to file that over this way and actually lines up perfectly with 40 grams so at most if I have 100 grams of water and Hunger Game glass of water is 100 mL of water what's the most now if salt I can solve is 40 grams  hi guys this is what the side Lily crab looks like for gases is are different than than solids in the fact that they're actually very very soluble in cold water and gay the colder the the solvent the will they are you'll notice every single one of these has a higher solubility when the temperature going out of temperature the temperature is low and as the temperature increases SATA 45 or 46 you'll notice of the temperature affect the solubility and I have a decrease in Sia bility as the temperature increase this is actually very very big applications are a very big applications especially for this guy right here oxygen okay during the summer time you know any aquatic Aquatic Life that actually uses oxygen and needs it in the summer time they're going to have a hard time finding that because the auction level decreases significantly because of the summertime you have a hotter like body of water they are Pond or a lake when that pain Turley keeps up really what's happening is that the level of oxygen is dropping so if you're a fish and you're swimming around that Lake you're going to say oh my gosh this water is hot I go fight some cold water because in the colder water there's more auction for them so fish in the summertime 10 to swim down deep or not just cuz it's cold and it feels the really sweet because I can breathe better down there there's more oxygen dissolved in cold water than warm water so once again guys the whole gist of today was to look at Lakers and get ahold of how does temperature affect solubility and now it affects my ability how can I express it in a graph right what is a very very useful tool for scientists to compare and predict different amounts it just a great way for scientist Express information about the side bility of a substance I do want to catch two things here is that one you have positive slopes and negative slope just Baron line yes most substances increase inside Billy with reach temperature but there are certain substances is all gases that do the opposite as a temperature increases their sideloaded decreases turn again what's up catch you next time

Uploaded by Laura Houston.

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Solutions: Solubility Curves

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