Take the sample containing the nitrate ions in a test tube. Ferrous sulphate is prepared fresh and taken in another test tube. The freshly prepared ferrous sulphate solution is mixed with the test tube containing the given sample. Concentrated sulphuric acid is added along the sides of the same test tube. The test tube must be tilted a little while concentrated sulphuric acid is added. This is done so that the acid goes into the test tube’s bottom, resulting in the formation of a brown-coloured ring exactly at the junction of the two layers. Once the brown ring is formed in the test tube, do not shake the test tube. This might make the brown ring disappear into the solution.
0:02 . If the test begins with Heating C. It means that we will not test for nitrate ions. Since the gases Nitrogen oxide and oxygen will be evolved. We will only test for lead ions and carbonate ions. That means after hearing, we would be asked to add dil nitric acid to dissolve the mixture of lead oxide and sodium carbonate that remains. Then further test with sodium hydroxide and and ammonia will follow. Or instead of adding dil acid to the pbO and Na2CO3, we may be asked to add water. What do you think?
You are very correct @Sesughahowua! Adding water or dilute HNO3 is a possibility, which we addressed in the 3rd Part of this Series - Likely 2024 Qualitative Analysis Questions. Kindly find the link below: ruclips.net/video/Ctn_w9G4ik0/видео.html
What you have in the instructions is K2Cr2O7, but what is normally used in the test you just described is K2CrO4, and they are not the same thing. So, I don't think they would give the same result, though I stand to be corrected!
Please I thought the difference between Pb²+ and Al ion is that lead ion gives a chalky precipitate with NaOH while Al ion give a gelatinous precipitate?
Yeah, that's is a preliminary difference, but the confirmatory test for Pb2+ is reaction with dil. HCl to form a white ppt. of PbCl2, while Al3+ gives no visible reaction.
Take the sample containing the nitrate ions in a test tube. Ferrous sulphate is prepared fresh and taken in another test tube. The freshly prepared ferrous sulphate solution is mixed with the test tube containing the given sample. Concentrated sulphuric acid is added along the sides of the same test tube. The test tube must be tilted a little while concentrated sulphuric acid is added. This is done so that the acid goes into the test tube’s bottom, resulting in the formation of a brown-coloured ring exactly at the junction of the two layers. Once the brown ring is formed in the test tube, do not shake the test tube. This might make the brown ring disappear into the solution.
Yes, it's a possibility because NECO have done it before. In that case, you may be the one that would be adding the acid for the students. Thanks for watching!🙏
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Thanks sir
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God bless you sir. Thanks for breaking it down
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Take the sample containing the nitrate ions in a test tube.
Ferrous sulphate is prepared fresh and taken in another test tube.
The freshly prepared ferrous sulphate solution is mixed with the test tube containing the given sample.
Concentrated sulphuric acid is added along the sides of the same test tube.
The test tube must be tilted a little while concentrated sulphuric acid is added. This is done so that the acid goes into the test tube’s bottom, resulting in the formation of a brown-coloured ring exactly at the junction of the two layers.
Once the brown ring is formed in the test tube, do not shake the test tube. This might make the brown ring disappear into the solution.
Yeah, you are very correct! This has been demonstrated in the second part of this tutorial. Thanks for watching!🙏
Thank you
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Well done sir... Perfectly explained
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I really appreciate
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Science chef, Sir you are doing well. straight to the point explanation ❤
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0:02 . If the test begins with Heating C. It means that we will not test for nitrate ions. Since the gases Nitrogen oxide and oxygen will be evolved. We will only test for lead ions and carbonate ions. That means after hearing, we would be asked to add dil nitric acid to dissolve the mixture of lead oxide and sodium carbonate that remains. Then further test with sodium hydroxide and and ammonia will follow. Or instead of adding dil acid to the pbO and Na2CO3, we may be asked to add water. What do you think?
You are very correct @Sesughahowua! Adding water or dilute HNO3 is a possibility, which we addressed in the 3rd Part of this Series - Likely 2024 Qualitative Analysis Questions. Kindly find the link below:
ruclips.net/video/Ctn_w9G4ik0/видео.html
All correct guys..We should also not forget to educate the students between dry and wet tests.
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your like well deserved 😊❤
🤜🤛❤️
Good job sir. But would like to see you carry out the brown ring test with the filtrate from the mixture of the two salts.
Sure, that would be uploaded tomorrow! Just turn on your notification bell!
The test tube should be held in a slanting position. Good job sir.
Yes, you are very correct! Thank you for watching!🙏
Pls sir what is the difference between qualitative analysis and volumetric analysis
Qualitative analysis is also known as salt analysis, while volumetric analysis is also known as quantitative analysis (acid-base titration)
You are very correct!👍
They could also ask them to test the Pb2+ with KI which gives a bright yellow ppt
Yeah, it's also a possibility!
KI is not a bench reagent for this year. Rather they'll use potassium dichromate to confirm Pb²+, it will still give yellow ppt
What you have in the instructions is K2Cr2O7, but what is normally used in the test you just described is K2CrO4, and they are not the same thing. So, I don't think they would give the same result, though I stand to be corrected!
Please I thought the difference between Pb²+ and Al ion is that lead ion gives a chalky precipitate with NaOH while Al ion give a gelatinous precipitate?
Yeah, that's is a preliminary difference, but the confirmatory test for Pb2+ is reaction with dil. HCl to form a white ppt. of PbCl2, while Al3+ gives no visible reaction.
Good day sir, please how many questions are we to answer from each section in the theory
What of the volumetric analysis
We are working on it!
If we are asked to use H2SO4 what would ge the inference?
If you are asked to use H2SO4 on what? Please can you shed more light on your question?
Sir please i thought its KMnO3 and FeSO4?.
That's for the volumetric analysis!
Take the sample containing the nitrate ions in a test tube.
Ferrous sulphate is prepared fresh and taken in another test tube.
The freshly prepared ferrous sulphate solution is mixed with the test tube containing the given sample.
Concentrated sulphuric acid is added along the sides of the same test tube.
The test tube must be tilted a little while concentrated sulphuric acid is added. This is done so that the acid goes into the test tube’s bottom, resulting in the formation of a brown-coloured ring exactly at the junction of the two layers.
Once the brown ring is formed in the test tube, do not shake the test tube. This might make the brown ring disappear into the solution.
ok😀
🙏😂
What if the the filtrate is heated
Good day sir, please is waec chemistry practical instructions out
Good evening Al-ameen. Yes, it is!
Yes
Okay sir, do you mean this is in line with 2024 practical instructions?
Yes, it is!
Is this for alternative B own??
No, Alternative B would be released this week! Subscribe and turn on your notification bell!
Good day sir.....pls help with titration
That will be done immediately we are done with the qualitative analysis!
Will waec allow students to use conc H2SO4?
Yes, it's a possibility because NECO have done it before. In that case, you may be the one that would be adding the acid for the students. Thanks for watching!🙏
Exactly my taught. Will the students be as careful as expected when handing the acid🤔
Never rule out anything. It's better to be over-prepared than being caught "unfresh" like the 5 f**lish virgins!🙏
@@TheScienceChefAcademy😂 You are blessed with wisdom!!
please what i