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AS Chemistry Practical - Paper 34

Messages
172
Reaction score
71
Points
38
Btw, I didn't understand why they chose the cation is Lead (Pb2+), based on the fact that
Na2CO3 & Na2SO4 react with FB6 to give a white ppt!? (Like, anything gives white ppt..)
And then based on reaction of NaOH with FB6, to we didn't test with NH3, so how do we know which metal is used?
heheheheh I just understood my mistake :D
By the reaction of SO4^2- with Pb^2+ (As in page 9), white PPT is given :D
 
Messages
107
Reaction score
30
Points
38
how will i know which gas is evolved in the experiment?

You have to do the gas test! if a colorless gas is released, first do a splint test then a litmus test
And if you see that a brown gas is evolved, you can say that it is NO2 :)
 
Messages
17
Reaction score
17
Points
3
Unless some CIE guy comes and gives away the details, we can't be sure about the reagents to be tested. And frankly, it doesn't even matter if we did, all we need to know are the procedures and we gotta do them anyways. Just google the basic colour changes and keep it in mind. I also heard they will provide with three litmus papers. So I think we need to test for gasses by thermal dec as well. Ad all we can do is google measuring enthral pay change and titration procedures. And guys, YouTube is one hell of resource for the methods, descriptions in full step by step, ******* cool, I say!
 
Messages
172
Reaction score
71
Points
38
You have to do the gas test! if a colorless gas is released, first do a splint test then a litmus test
And if you see that a brown gas is evolved, you can say that it is NO2 :)
But be careful not to be fooled, NaBr can also react with H2SO4, producing NahSO4 and HBr, and the HBr again gets oxidized (reducing H2SO4), and producing SO2, and Br2 gas!! (Brown)
 
Messages
172
Reaction score
71
Points
38
Unless some CIE guy comes and gives away the details, we can't be sure about the reagents to be tested. And frankly, it doesn't even matter if we did, all we need to know are the procedures and we gotta do them anyways. Just google the basic colour changes and keep it in mind. I also heard they will provide with three litmus papers. So I think we need to test for gasses by thermal dec as well. Ad all we can do is google measuring enthral pay change and titration procedures. And guys, YouTube is one hell of resource for the methods, descriptions in full step by step, ******* cool, I say!
Dude it's Enthalpy :D
 
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