Chemistry: Post your doubts here!

[Tauqir_hamed]

Can anyone refer me any source to learn HNMR and CNMR
It will be a huge help.

There is this youtube channel named " E. Rintoul " . Watch his videos

 

[A*****]

Did it say " this behavior of ammonium with WATER '' . coz if it didn't.. will the equation NH4+ + OH- ----> NH3 + H2O work ?? i dont know whether it specifically said '' water ''

Water wasn't specifically mentioned but I'm not sure about this equation

 

[Tauqir_hamed]

Water wasn't specifically mentioned but I'm not sure about this equation

If water wasn't mentioned, then I think this equation will work.. I wrote NH3 + H2O <---- ------> NH4+ + OH- .. you can see that NH4 + has donated a proton to OH- and has thus formed NH3 + H2O.. if i am not wrong..
however, not sure whether water was mentioned or not..

 

[Holmes]

4BF3 + 3NaBH4 ---> 2B2H6 + 3NaBF4


Formula is C5H5N5
just count the number of each kind of atom

Actually the problem lies with H atoms my count says 4 so?

 

[amina1300]

well yes they make a balanced paper for those who appear in the same session so that the threshold is not too high nor too low
so this could be a possibility

So this means if there was only 10% organic in P2 then most of the P4 will be organic based as normally 60% is organic in P4 ?!!

 

[Fardeen3342]

can someone help with this I don't get the concept behind it

help

 

[anastasia grey113]

Actually the problem lies with H atoms my count says 4 so?

oh how did u balance it?

 

[Fardeen3342]

Last question the structure of L too please

 

[anastasia grey113]

can someone help with this I don't get the concept behind it

only phenol and carboxylic acid react with alkalis
and only amine reacts with cold acid
and only those having amine groups will be soluble in acid and those having carboxyl group or phenol will be soluble in base as they will ionise

 

[anastasia grey113]

Last question the structure of L too please

Remove the Cl and the Ag and join the remaining together

 

[Fardeen3342]

View attachment 63519
Remove the Cl and the Ag and join the remaining together

Thank you

 

[Fardeen3342]

can you help with b(iii)

 

[MIK3Y.]

For b why is n=1 should it be n=2 ??

 

[Fardeen3342]

View attachment 63522View attachment 63524
For b why is n=1 should it be n=2 ??

For b why is n=1 should it be n=2 ??[/QUOTE]
my weird method
ok so in the question its clearly stated that cr-cl in the complex does not react . hence the values given in the table are for cl(3-n) that reacts with ag . so now the moles you calculated in the previous question (3.75*10^-3) compare that with each isomer . For A its 1:1 ( same moles ) so we have to make the cl outside the complex =1 and to do that we make n =2 . for isomer b it's 1:2 (7.5/3.75) that means that there will 2 chlorine that react hence to make cl2 we need to make n = 2

 

[Fardeen3342]

so just clarify something with me the 4.0 peak is due to ch-o yes ? because ms says just ch but just ch chemical shift isnt in that range

 

[Fardeen3342]

for b (ii) ms states that remaining is 10.8/1000 * 0.5 but isnt the amount reacted equal to that ???!

 

[qwertypoiu]

for b (ii) ms states that remaining is 10.8/1000 * 0.5 but isnt the amount reacted equal to that ???!

Imagine:
100 units of NaOH is reacted with SO2 and HCl. 90 units was consumed in this reaction. 10 units of NaOH remains in the solution.

This is called EXCESS NaOH was reacted with SO2 and HCl.


Now in real life we don't know that 90 units of NaOH reacted with SO2 and HCl. What we know is that we started with 100 units.

By doing titration with the remaining solution soup, we can know that 10units of NaOH REMAINED in the solution. This is the excess amount.


Using the above two information, we can do the magic: 100-10= 90 units of NaOH.

 

[Holmes]

oh how did u balance it?

Girl I am talking about the question to find molecular formula

 

[Holmes]

March 2017 Q6f(iii)


March 2017 Q7e(i)

Help me out any Chem Expert
anastasia grey113

 

[Zaki ali asghar]

for NMR, say that the peak splits into three, so there are 2 H on the adjacent carbon atom but what if there are two adjacent carbon atoms?