Assume that you have an aqueous mixture of BaCl2 and CuCl2. How could you use a precipitation reaction to sepa-rate the two metal ions?

Video transcript

Hey everyone in this example we need to select the below re agent. That would be used to separate our two cat ions from a solution of silver nitrate and rubidium permanganate. So we want to focus on the Catalans in the listed compounds. So they mentioned silver nitrate. And within this compound we have the silver plus one carry on. And in rubidium permanganate we have the rubidium plus one cat ion. Now we want to basically think about the fact that these Catalans are going to be in a solution and so they're floating around in the same solution. So we have a G. Plus and R. B plus and a beaker. And the only way that we can separate these two catamarans from one another is to form a precipitate. And so we're going to want to add in an an ion that is going to be insoluble when it's combined with one of these cat ions. And so that would form a solid precipitate compound at the bottom which we can use tongs to remove from our solution, thereby removing one of the cat ions from the solution. Now the only exception are group one a cat ions and in this case we do have a group one A carry on. When we look at our periodic tables, we would find rubidium in group one A. And so because this is a group one, a cat ion, we can say that therefore it's going to always be soluble when it's bonded to a an ion. So it's always soluble. So we want to focus on what would be bonding to our silver cat eye on here to form a precipitate. And based on our answer choices, we're going to analyze each of these and ions. So in answer choice A. We have the per chlorate an ion and we want to recall that perk Low rates are soluble in general according to our Celje bility rules. So we can go ahead and rule answer choice A. Out. We also have an answer choice B. The nitrate and ion. And we want to recall our cell viability rules for nitrates which states that all nitrates are soluble. So that goes for also answer choice C. Where we have two moles of the nitrate and that applies here as well. So we can rule out B. And C. And that leaves us with anti choice D. As the only correct answer choice where we have a sulfate and so the sulfate and I and we want to recall are generally going to be soluble so sulfates are soluble. But there's exceptions with salt as well as Catalans like silver where silver is going to be slightly soluble and so because it's only slightly soluble it's more so going to lean towards forming a solid precipitate. And so we would imagine the following reaction where we have the precipitate that forms where we combine silver and sulfate forming silver sulfate. And so this would be a G two S. 04 when we crossed the charges because actually sulfate is S. 042 minus. So sorry about that. And what we would do is according to our cell viability rules, we see that because we have silver bonded to our sulfate, this is therefore going to be an insoluble solid precipitate because it's only slightly soluble. And so we would form an equilibrium reaction where we form two moles of our silver Pluskat ion and one mole of our sulfate and ion. And so these ions are both going to be a quiz because they're ions ions are always Aquarius and soluble. And so this is what we're adding in. Two forms are solid precipitate with our cat eye on here so that we can remove this from our solution. So this is going to be the cattle on that we are able to remove from the solution. And so our final answer choice from this example is going to be answer choice D Where we have potassium sulfate as the re agent that we would add in to form our solid precipitates silver sulfate to remove the silver cat ion from our solution. So if you have any questions, please leave them down below. Otherwise I will see everyone in the next practice video