Dilutions

a standard, sometimes referred to as a stock solution, is a concentrated solution that will be diluted for some laboratory use later on. And we're gonna say dilution is just the addition of more solvent, usually water to a solution in order to create a lower concentration. So, if we take a look here, we have our purple solvent here, purple solution. Actually, it's pretty dark purple, meaning that it's concentrated. And what we're doing here is we're slowly adding more water, so we're adding water to it to diluted. As a result of this, it goes from being a dark purple to a lighter type of fuchsia or purple. That's showing us that it's not as concentrated as it was before. So here this represents our diluted soldier. So, just remember when we're talking about dilution, we're just talking about adding water to our original solution to make it less concentrated.

in this example question. It says, if each sphere represents a mole of salute from the images provided below, arrange the solutions from least concentrated to most concentrated. Alright, so least concentrated is the same thing as saying the lowest polarity most concentrated means we have the highest polarity. Now remember, Polarity itself represents moles of solute divided by leaders of solution. So if we take a look here for a a has in it 12345 Sears. So that would be five moles of solute divided by one leader of solutions. So that'd be five Mueller for B b is 123 spheres. So that's three moles of solute over to leaders of solutions that be 1.5 Mueller and then finally see, we have 123456 spheres. So six moles divided by three leaders of solution. So that's two more so arranging it from the lowest polarity toe highest polarity, we're going to say the order would be be then see, and then finally a would have the highest polarity

So at this point we know that a dilution makes our solutions less concentrated. It takes us from a larger, more clarity value toe a smaller polarity value. We're gonna say dilution can be expressed by the following equation. So it's M one V one equals M two V to hear M one and V one represent the polarity and volume before dilution. While M two and V two are after the dilution, we're going to stay here. M one is before a solvent has added So m one which is the more concentrated solution is always larger than M two, which will be the diluted solution. Now the two represents your final volume. And how exactly did we get to be too? Well, we started out with an initial volume and we added water to it. So the two equals the one plus the volume of solvent added

in this example question. It says what volume and milliliters off 5.2 Mueller hydroponic acid must be used to prepare 3.5 leaders off 2.7 Mueller hydroponic acid. Now, how do we know this is a dilution question? Well, typically in a dilution question, we're only talking about one compound, and with that one compound to be talking about dilution, we tend to deal with two more clarity's. Okay, so the fact that we're dealing with just hydroponic acid and we have two more clarity is associated with it is a strong indication that we're dealing with the dilution. So that means we're gonna use em. One V one equals M two V two. Now, remember, M one is larger than M two because I m. One represents your concentrated solution before you've begun dilution. Because of this 5.2 Mueller has to be our M one. It's the larger polarity associated with m one is V one. We don't see any number around it, So v one is what we're looking for now. Remember also that the word off when it's in between two numbers, that means multiply. We're going to say here that this is the smaller polarity. So this has to be m two. So that's our diluted. More clarity. We're multiplying it with 3.5 leaders. So based on the dilution equation, 3.5 leaders has to be V two. We're gonna isolate V one, so divide both sides by 5.2. Moeller the mole. Aridjis, cancel out and look, we'll have V one. But here it will be in leaders. So that comes out to be 1.8173 leaders. We want the answer milliliters. So just do a quick metric prefix conversion leaders on the bottom metal leaders on top one Millie is 10 to the negative three. So leaders cancel out. And that comes out to be 1817. mL here, 5.23 point five and 2.7 All have to sig figs. So if we wanted to significant figures here, we just write this as 1800 middle leaders 1800 mL as our final answer. So just remember, when we're dealing with one compound and we have different polarities, that's a strong indication that we're dealing with a dilution equation, So use the dilution formula and solve for the missing variable