Iron granules means Iron metal. B contains Fe2+ and the atomic mass of Fe is the same as its ion, hence it is provided for you in the bracket. The question centers on the concentration of Fe2+. The question is not interested in what compound is Fe2+ obtained from. As a matter of fact, the specimen B given in the instructions anhydrous FeSO4 is not part of the question. Using the molar mass of FeSO4 is definitely wrong here because, WAEC changed the substance. That is the reason why the molar mass of FeSO4 was not provided neither did they provide the relative atomic masses of S and O.
Sorry, you are the one wrong. We don't come online to solve what we are not sure of neither are we armatures. If you are solving the question based on the instructions given in the specimen, you are definitely scoring 0%. Mind you that solution B in the question is not FeSO4 but an Fe2+ solution prepared from dissolution of iron metal. If you claim to be right, drop your solution here, let us digest and point out your errors. We don't copy others but give absolute correct answers
@@bestsciencebrain The formula for calculating concentration in mol/dm3 when the mass of the substance is given is gram conc./molar mass but first You have to convert 3.8g that is dissolve in 250Cm3 to dm3 which will be 15.2g, there after you divide 15.2/molar mass of Fe2+ (56)=0.271mol/dm3 of Fe in the solution
@@WilliamsAnaiho No no no. This is very wrong. You don't work by formula but by understanding the question. You are asked to calculate the concentration of Fe2+ (B) in moldm-3 and not the concentration of Iron granules (Metal) in moldm-3. Of what use is the CA there? Have you considered the impurity that would be in 3.8 g of the iron granules. Did they question specify that pure iron granules was used in dissolution. This is like a case of when you are told that 5.2 g of impure NaOH was dissolved per dm3 and you go on to find its concentration per dm3 using 5.2/40, neglecting the trace impurities. The value of CA was given to you directly as 0.020 moldm-3, so you obtain the actual concentration of Fe2+ in the solution using the titration formula and not using the mass of iron metal. The mass of iron metal is used in question biv to find the % of Fe2+ in the iron. Question 1biv even suggests to you that 3.8 g is not the mass of pure iron only and that is why you are asked to find the % of Fe2+ in the iron granules. Concentration gives the amount of the pure substance only, excluding traces of impurities. Quad Erat Demonstradium
@@bestsciencebrain the question asked does not have anything to do with the titre value, from the instructions sent from waec which of the salts has a higher mass to be dissolve, the stated conc. of A there would only help you to find the mass of dissolve A and not to be used to calculate the concentration of B
Solutions the same as WAEC marking scheme. You can go and verify as marking is going on now for the doubting Thomases
Can we write percentage purity instead on percentage of fe2+
As long as your working is correct
You didn't upload a practice session this year..... Missed your content.
Wow you missed a lot. Check my channel. I did and still going to do that of Alternative B including physics
Perhaps you didn't subscribe to the channel, you would have seen the whole uploads. I did alot
If B is a solution of 3.8g of fe tablets dissolve in 250cm3 of solution. Why using 56?
Iron granules means Iron metal. B contains Fe2+ and the atomic mass of Fe is the same as its ion, hence it is provided for you in the bracket. The question centers on the concentration of Fe2+. The question is not interested in what compound is Fe2+ obtained from. As a matter of fact, the specimen B given in the instructions anhydrous FeSO4 is not part of the question. Using the molar mass of FeSO4 is definitely wrong here because, WAEC changed the substance. That is the reason why the molar mass of FeSO4 was not provided neither did they provide the relative atomic masses of S and O.
@@bestsciencebrain like the granule is only iron. Not iron compound.
Sure Iron granules or granulated iron is just iron metal in smaller sizes
@@bestsciencebrain that means B is a solution of Fe granules.
@@clementbiola3236 Fe2+ from iron granules
Check ur no 1bii well
1bii is 100% correct. You are calculating concentration of B (Fe2+) per dm3 not that of iron granules nor FeSO4
You solving on bi is wrong
Sorry, you are the one wrong. We don't come online to solve what we are not sure of neither are we armatures. If you are solving the question based on the instructions given in the specimen, you are definitely scoring 0%. Mind you that solution B in the question is not FeSO4 but an Fe2+ solution prepared from dissolution of iron metal.
If you claim to be right, drop your solution here, let us digest and point out your errors. We don't copy others but give absolute correct answers
@@bestsciencebrain The formula for calculating concentration in mol/dm3 when the mass of the substance is given is gram conc./molar mass but first
You have to convert 3.8g that is dissolve in 250Cm3 to dm3 which will be 15.2g, there after you divide 15.2/molar mass of Fe2+ (56)=0.271mol/dm3 of Fe in the solution
@@WilliamsAnaiho No no no. This is very wrong. You don't work by formula but by understanding the question.
You are asked to calculate the concentration of Fe2+ (B) in moldm-3 and not the concentration of Iron granules (Metal) in moldm-3. Of what use is the CA there?
Have you considered the impurity that would be in 3.8 g of the iron granules. Did they question specify that pure iron granules was used in dissolution.
This is like a case of when you are told that 5.2 g of impure NaOH was dissolved per dm3 and you go on to find its concentration per dm3 using 5.2/40, neglecting the trace impurities. The value of CA was given to you directly as 0.020 moldm-3, so you obtain the actual concentration of Fe2+ in the solution using the titration formula and not using the mass of iron metal.
The mass of iron metal is used in question biv to find the % of Fe2+ in the iron. Question 1biv even suggests to you that 3.8 g is not the mass of pure iron only and that is why you are asked to find the % of Fe2+ in the iron granules. Concentration gives the amount of the pure substance only, excluding traces of impurities. Quad Erat Demonstradium
@@bestsciencebrain the question asked does not have anything to do with the titre value, from the instructions sent from waec which of the salts has a higher mass to be dissolve, the stated conc. of A there would only help you to find the mass of dissolve A and not to be used to calculate the concentration of B
@@bestsciencebrain you can also check more on waec past questions and answers with similar questions