NECO June 2024 Chemistry Practicals* (Qualitative Analysis on Specimen C and D)

[@AffectionateBluebonnetFl-mu7zy]

Thank you very much sir, God bless you

[@bestsciencebrain]

You are welcome

[@EternalScienceAndTech]

Such a distilled knowledge. Thanks

[@bestsciencebrain]

We appreciate

[@WunennaAmbrose]

So much appreciate sir.God bless you

[@bestsciencebrain]

You are welcome

[@KelechiEweama-wx5nu]

Thanks for your wonderful lesson.

[@bestsciencebrain]

We appreciate your comment. Thanks

[@faavewezy1922]

Thank you so much God bless you

[@bestsciencebrain]

We appreciate

[@spiritandlifechannel3039]

What are the specifications that you used to prepare ammonia, trioxonitrate(v) and sodium hydroxide reagent.

[@bestsciencebrain]

AgNO3: 1.7 g in 500 cm3 of water NaOH: 2 g in 250 cm3 of water NH3: 10 ml in 20 ml of water. You can still increase the volume of water but make the NH3 solution moderately concentrated for effectiveness. Reagents especially NaOH and NH3 should be prepared freshly as they are required for optimum results while AgNO3 should be stored in amber coloured reagent bottles to minimize light decomposition

[@spiritandlifechannel3039]

​@@bestsciencebrainthanks A million.

[@spiritandlifechannel3039]

Hope 2M is OK for making acid bench reagents.

[@rosemaryonyeje200]

Good afternoon sir. Is it any inorganic salt that is used as C or you already know the salt to be used? Because I don't understand quantitative analysis or salt analysis.

[@bestsciencebrain]

The analysis shows confirms the salt. From the analysis C contains Zn2+ and Cl- ions. So C is ZnCl2

[@YemiAyinde]

Well done,good work

[@bestsciencebrain]

We appreciate

[@sesughahowua5745]

Hello. Is Neco chemistry specimen for 2024 out already?

[@bestsciencebrain]

100%

[@KelechiEweama-wx5nu]

Sir thank you very much.pls am a teacher.i.l want to know if D is the normal powdered milk that we drink

[@bestsciencebrain]

You are welcome. D is normal powered milk but you are going to make a solution of it and provide it as a solution to the students.

[@OkoliBiere]

I think ammonia should evolve on heating if protein is present

[@bestsciencebrain]

Are you saying something practicable or what you think??

[@ErisMaxwell]

There is no AgNO3 in the reagents provided

[@bestsciencebrain]

It doesn't matter. You are expected to have all common laboratory reagents available. Thanks

[@blessingokoro6616]

Thank you so much sir for this I want to ask a question, how do I prepare sodalime, even though it will be not be use in the practical, I just want to prepare it since it's part of the requirements I will appreciate a reply Sir Thank you sir How many grams am I mixing in 100cm or 200cm in water

[@bestsciencebrain]

Thanks for your comment. You can prepare a standard solution of soda lime by dissolving 8 g of soda lime in 250 cm3 of water or 32 g in 1000 cm3 of water. Soda lime is a mixture of sodium hydroxide and calcium hydroxide. Equal (intimate) mixture of the two compounds can also give you soda lime.

[@blessingokoro6616]

@@bestsciencebrain thank you so much Sir for the reply I really appreciate🙏 That means 4g of sodium hydroxide and 4g of calcium hydroxide

[@JeremiahGoddey-qn9cw]

Thank u so much If u can answer me fast Which salt are we testing for Is it two inorganic salt

[@bestsciencebrain]

C is ZnCl2: Zinc chloride. D is not a salt. D is a solution of powdered milk. Thanks

[@JeremiahGoddey-qn9cw]

Ohk tnx I just understand now

[@EmekaAnthony-hv8be]

You really need a bottle of wine and a plate of food 😂😂 for this , thanks a million times.

[@bestsciencebrain]

Thanks we appreciate

[@angelamuokwue7236]

What test can it be use for ie the soda lime

[@bestsciencebrain]

I don't see its relevance here. Thanks

[@rosemaryonyeje200]

How did you know?

[@bestsciencebrain]

How do I know what???

[@CLEMENTONOJA-zk8ir]

Know the questions

[@YusufNafisah-xr3xh]

How can i prepare Aq NaOH

[@bestsciencebrain]

4 g of NaOH in 500 cm3 of water will give you a moderately concentrated solution of 0.2 M. Prepare freshly at the time of use due to it's deliquescent nature.

[@spiritandlifechannel3039]

Can we also use this 0.2M concentration to prepare other aqueous reagents?

[@bestsciencebrain]

Check your comment, it has been replied

[@IbrahimLaaro]

Thanks for the good work.

[@bestsciencebrain]

We appreciate

[@ElizabethDuru-h7i]

What of the soda lime ,where do we use it

[@bestsciencebrain]

Question has been dropped. Screen our videos

[@bestsciencebrain]

Question has been dropped. Screen our videos

[@EricDarlington-h4f]

Volume of CO2 gas liberated at s.t P is 0.0137

[@bestsciencebrain]

Under what context. We don't understand what you are talking about

[@rosemaryonyeje200]

What salt is that C?

[@bestsciencebrain]

Check your comments and the reply.

[@userIkechukwu]

Zinc ion, aluminum ion, and not zinc (ii)ion ,or aluminum (iii)ion. Zinc and aluminum are not having variable valency.

[@benedictanyanwu3976]

He is not wrong. You can not pronounce an ion without mentioning its valency or charge whether fixed or variable is inconsequential. Who gave you this rule? Based on what you are saying, so you go ahead and write Zb ion and Al ion as it sounds from your mouth. Don't correct someone that knows more than you.

[@bestsciencebrain]

​​​@@benedictanyanwu3976 Thanks for the reply Boss. When you are pronouncing chemistry terms, it should sound literal. This is practical lecture to fundamental students and not theory. Excluding the oxidation states of metals that have constant states can work in their compounds Eg ZnCl2 pronounced as Zinc chloride. Zinc (II) Chloride is also acceptable being specific Al2O3 pronounced Aluminium oxide, similarly being specific Aluminium (III) oxide is acceptable. However when the metals exist as separate cations, you can't pronounce them without mentioning their oxidation states ( the charges are the oxidation states not valency, they are two different things) Zn2+ is pronounced Zinc (II) ion not Zinc ion and Al3+ is pronounced Aluminium (III) ion not Aluminium ion (read my lips). Zinc ion could probably make a student write Zn+, Zn2+, Zn3+ etc, similarl explanation applies to Al3+ ion. This will jeopardize the student's chance of scoring. His point is more like telling a student to go and write "Zinc ion" and Aluminium ion" without specifying their oxidation states under the inference column thus making the student to loose his marks He is advised to gatecrash into WAEC and NECO coordinaton and markings late June and July respectively and learn more because he appears to be a new hand in the field and has been reading textbooks and online source materials without proper guidance. Quad Erat Demonstradium Thanks once again🎉😊

[@opec1989]

For Specimen D, teachers were asked to provide students with a solution of D, do you think they will ask the students again to add 2cm3 of water?

[@bestsciencebrain]

​@@opec1989 Thanks for your correct observation and comment. It was an oversight from us. D is to be provided as a solution so there would be no need to dissolve D in water

[@passwellsciencechannel146]

Sodium dioxozincate and sodium tetraoxozincate. During your explanation you made a slip of the tongue.

[@rosemaryonyeje200]

Why is it only Zn2+ confirmed

[@bestsciencebrain]

Review the question and take your time to understand the video. C is a simple inorganic salt. Do you expect a normal salt to contain two cations or did you watch the confirmation of the Chloride anion?

[@angelamuokwue7236]

Please, in this NECO white paper, we are asked to provide soda lime. What test can it be for. I am a Chemistry teacher . And how can it be prepared. Thanks

[@bestsciencebrain]

Thanks. Soda lime can be used to absorb CO2. I don't see its relevance in the provided specimen.

[@angelamuokwue7236]

Thank you sir. Can l get your phone number please

[@blessingokoro6616]

I think we can use NaOH in place of sodalime