NECO CHEMISTRY PRACTICAL 2026 SALT ANALYSIS

[00:00:00]Yes, you're welcome everyone to IMAX.

[00:00:03]And then today we'll be looking at the NECO chemistry practical 2026 this very time on salt analysis. Okay? All right.

[00:00:12]So, here we've been asked to provide um the salt sample copper two sulfate okay? As the name is here to be labeled C.

[00:00:23]All right. Now, actually this salt should not be exposed to the students.

[00:00:27]Okay, so that means that every test that will be carried on, you know, successively or subsequently as the case may be would be test on the component ion in this very salt. Okay, so if this salt dissociates for example okay, so we would have such as this copper two ion and tetraoxosulphate six ion. Okay? That's Cu2+ and SO42-. So, basically the test we'll be looking at subsequently now will be tests that are or that concerns these two salts. Okay?

[00:01:04]So, all right. So, we'll begin the very experiment right here.

[00:01:08]Okay, so we're not here for any assumptions. We're here to do the practical analysis for the salt. So, we've been asked to provide that salt and label it C. So, we've got the salt here on the filter paper here as we can get right there on the screen. Okay? So, here the first thing is C put C is spatula full of C in a test tube. So, let me get that done.

[00:01:35]Let me get um this very time I'm working with a spatula. Okay, so here I have the salt sample in the test tube.

[00:01:47]All right. So, we'll be asked to add a specific volume of water. You may, you know, um you know, um do exactly the volume. You may not do.

[00:01:56]The does not affect the subsequent test anyway. All right, so let's just add considerable number of of volume of water.

[00:02:04]So here I've got the water.

[00:02:06]Added.

[00:02:11]The next thing we do is we have to stir and evaluate what happens after adding water to the salt sample, C.

[00:02:22]It's all right, so I think we're getting that right there from the screen.

[00:02:27]So we have the salt trying to dissolve.

[00:02:30]It's dissolving gradually.

[00:02:33]All right, so as the solution becomes pale blue in color. So here we're having the salt to dissolve to be soluble, not sparingly soluble or insoluble. It is soluble and giving rise to a pale blue solution.

[00:02:48]So I'm waiting I'm waiting for the rest of the solid behind of beneath the test tube to get you know, dissolved. So that we can make the good correct conclusion.

[00:02:59]All right.

[00:03:02]All right, so here I'm trying to get that dissolved.

[00:03:06]So we can get that solution in the test tube right there on the screen.

[00:03:10]All right, so I'm sure we can evaluate the color there. It's giving us a pale blue. A pale blue solution.

[00:03:17]So that means that C, when dissolved in water, we observe a All right, so let me stand this way.

[00:03:28]Salt C dissolves completely.

[00:03:36]Salt C dissolves completely.

[00:03:38]Okay.

[00:03:40]Forming a pale blue solution.

[00:03:47]That's the correct observation after the dissolution of the salt C in specific volume of water.

[00:03:55]All right. So, the next thing we have to do here is to add to test with litmus paper. So, what is our inference from this observation? Every inference every observation would have a conclusion to draw from there. So, seeing the salt dissolved completely and giving rise to a pale blue solution, we suspect copper two ion. So, we say copper two ion or rather Okay, we can actually come this way and say that salt C is a soluble is a soluble salt.

[00:04:31]Okay. Salt C is a soluble The The The The question here is actually to deduce if the salt is soluble or not soluble.

[00:04:41]So, that should be the very first inference if we were asked to add water or any solvent to dissolve it. So, salt C we discover it is a soluble salt. Now, then the next question is we have to add or test with litmus paper. Now, since we do not know if it's going to be acidic eventually or basic, so it is expedient you have the two litmus paper tested with it at the same time.

[00:05:04]So, I've got my litmus paper here.

[00:05:07]Here, I've got the blue So, I need the blue as well as the red.

[00:05:13]Each of them to be tested at the same time with the solution.

[00:05:20]So, I've got the two litmus paper here.

[00:05:22]I'm sure we can get the color on the screen before the test. Here, we've got here to be the blue and here to be the red. So, I can have the two of them stick inside the test tube while it makes contact with the solution.

[00:05:37]While it makes contact with the solution.

[00:05:40]Okay. So, I'm trying to get it in contact with the solution with the copper two you know, aqueous solution. Now, notice right there Okay, right on the screen, if you can get that, notice the blue at the tip.

[00:05:54]The lit- the blue litmus paper turns red at the tip, while the red remains red.

[00:05:59]So, that means or we conclude from there Now, testing the aqueous solution of the salt with litmus paper, we observe that it turns it turns litmus paper red.

[00:06:17]Now, you don't indicate if it is blue or red. You simply say it turns litmus paper red. That indicates nothing but acidic. So, we say that um Okay, we can say solution of salt C Solution of salt C is acidic.

[00:06:41]Solution of salt C is acidic. That's the correct inference from that very observation. And we would be asked to divide the sample into three.

[00:06:51]All right, into three segments. Okay, so I'll take them one after the other. The very first segment to be tested with um aqueous sodium hydroxide.

[00:07:01]So, I've been able to take a portion of the filtrate, so rather if you a portion of the solution, not filtrate this very time. So, don't mind me. All right, so we are to add the first portion, we are to add sodium hydroxide in drops.

[00:07:16]And subsequently, we'll do so in excess.

[00:07:18]So, then let's get that done and see the correct observation.

[00:07:23]So, I've got my sodium hydroxide here.

[00:07:25]Okay, here I add few drops of the sodium hydroxide.

[00:07:33]Okay, on adding sodium hydroxide in drop, I want to believe we can get those reactions at the at the screen there. Okay, notice a blue gelatinous precipitate at the top of the solution on the test tube.

[00:07:49]Blue gelatinous gelatinous. All right, so we have to do that also in excess.

[00:07:55]So, let me add in excess and let's see what becomes of that solution.

[00:07:59]On adding excess, I do not think that the precipitate will dissolve. As a matter of fact, it's becoming more solidified and crystallized. Okay, so that tells us that on adding excess sodium hydroxide, the uh the precipitate, you know, does not dissolve. So, here that means that From here, on adding sodium hydroxide in drops, we observe a blue Okay.

[00:08:28]Rather, a pale blue a pale blue gelatinous precipitate is formed.

[00:08:39]A pale blue gelatinous precipitate is formed. Then in excess, what happens?

[00:08:42]The precipitate the precipitate remains remains insoluble.

[00:08:50]The precipitate remains insoluble. So, what is our inference from that observation? Okay, we can we can you conclude that copper two ion is present.

[00:09:01]Copper two ion is present. Now, copper two is present, then the whole essence of having to put the sodium hydroxide in excess is to confirm or to deduce if the ion is actually amphoteric or not amphoteric.

[00:09:16]All right, so if we uh if on adding excess sodium hydroxide, the precipitate dissolves, that confirms the presence of an amphoteric, you know, ion. So, on adding excess sodium hydroxide and noticing that the precipitate remained, that tells us that the ion is non-amphoteric.

[00:09:36]Okay, A non-amphoteric ion, a non-ampho- -teric ion is present.

[00:09:48]Okay? Now, hydrogen and sodium hydroxide, it simply a different test to differentiate amphoteric and non-amphoteric ion. So, we're able to deduce that, we move on to the next test.

[00:10:01]All right. The next test, we collect another portion of that salt.

[00:10:06]Another portion of the salt. This very time, we are testing with aqueous ammonia.

[00:10:14]With aqueous ammonia. So, then let me get that um open.

[00:10:18]Um okay. Aqueous ammonia has a unique smell anyway. I'm sure we know that. It has a pungent, choking, irritating smell. Humorous like that of a urine anyway. So, all right. So, here we have to add uh drops of the aqueous ammonia into the solution. Drops.

[00:10:37]Now, at the Now, here on adding few drops of the aqueous ammonia, okay? We notice a precipitate.

[00:10:46]Precipitate. It became cloudy. That's the precipitate there. If I leave it for a while, it settles down on standing.

[00:10:53]So, that tells us that on adding aqueous ammonia solution in drops, we notice a pale blue gelatinous precipitate as well. So, now permit me to add in an excess. So, let's see it in excess and let's see what becomes of the solution.

[00:11:08]All right. So, here on adding excess excess aqueous ammonia, notice the coloration difference. Here we have a deep blue solution. The precipitate initially became soluble and forming a deep blue soluble solution. All right.

[00:11:27]So, that is exactly would be our observation. Here, okay? On adding excess ammonia, we notice a pale blue gelatinous, as well.

[00:11:41]A pale blue gelatinous PPT, okay, precipitate is formed.

[00:11:46]Is formed. Then, on adding it in excess, we notice that the blue precipitate, or rather, okay, let me have the blue out.

[00:11:56]I can say the precipitate dissolves.

[00:12:00]The precipitate dissolves, okay, forming a deep a deep blue solution.

[00:12:11]All right, the precipitate dissolves, forming a deep blue solution. What is our inference from that? We observe, or we conclude rather, that copper two ion is present.

[00:12:23]And here, on adding it to form a deep blue, that is a confirmatory test that copper two is the ion present. So, we simply say copper two ion confirmed.

[00:12:36]Copper two ion confirmed. So, we move on right away to the very last test. And that's going to be on the sulfate ion, SO4 2-. All right, so how do we confirm the presence of that? Now, let's get a clean test tube again.

[00:12:53]All right, so we have a portion of that salt, okay, have in that collected from the test tube, or in the test tube, rather.

[00:13:01]Here, the series of test involved um adding barium chloride solution, first in drop, then followed by adding um HCL, dilute HCL.

[00:13:17]Okay, now notice here, on adding barium chloride to the salt solution, you notice is white precipitate at the top of the solution in the test tube.

[00:13:31]So, we have a white precipitate at the top. Now, that tells us nothing that there are three ions we may suspect anyway, and the ions here, okay, we have a a white precipitate is formed.

[00:13:50]A white precipitate is formed. What are the likely ions that can form a white precipitate with barium chloride? We have the likes of SO42- ion, we have SO32- ion, in fact, we have carbonate ion, CO32-, okay, is present.

[00:14:09]Now, we are suspecting either of these three, but we are not sure which exactly it is.

[00:14:16]Now, the point is if it was if it was this and this, okay, or if it is any of them, they would equally have a white precipitate anyway, but here, if I now follow it by adding HCl, okay, to the white precipitate, if the precipitate dissolves on adding the HCl, then it will either be this or this.

[00:14:41]But, if the precipitate remains undissolved, it would definitely now be sulfate ion. Okay? All right, so here now, let's see what becomes of it on adding um dilute HCl to the white precipitate.

[00:14:58]Okay?

[00:14:59]What becomes of it on adding white precipitate? Okay, on adding white precipitate, I do not think right here, cuz I'm very close to the test tube, that the precipitate will dissolve on adding HCl. So, that concludes right right away that the ion that must have formed the white precipitate will be no other than the tetraoxosulphate (VI) ion. All right, so we said that on adding HCl, the white precipitate the white precipitate remains remains insoluble.

[00:15:37]Insoluble, so it confirms that of the SO4 2- ion is confirmed.

[00:15:45]Okay? So, that confirms the presence of that ion. All right, so now looking at the test that we've carried out, you know, so far, we've confirmed the presence of copper (II) ion. We just confirmed that of the sulphate ion, SO4 2-. That tells us that if I'm to combine the ions that have been confirmed confirmed, rather, in the course of the test, you discover that it is giving rise to the result of the copper (II), that is copper (II) tetraoxosulphate (VI) ion. And that's exactly what we've been asked to uh supply. Okay? So, at this point, I will put an end to the very test. I want to believe you actually found this um class very educating and and and helpful. If you truly do, or you truly did, as the case may be, please go right down there, subscribe to the YouTube channel, like and share, okay, to friends and families who will be writing exams in the course of time. We appreciate every one of us.

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