Nmr

[Mstoothlady2012]

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What will be the splitting pattern for 1,4-dimethylbenzene

I think it should be only 1 singlet. The hydrogens on the ring will not give any splits. The methyl hydrogens give singlet but since both methyl groups are similar (due to symmetry) they will only give 1 singlet right?

 

[Mstoothlady2012]

Isn't 1,2-dibromoethene Z configuration if both Br are facing up? Refer to Q 84 achiever test # 2.

 

[osimsDDS]

Isn't 1,2-dibromoethene Z configuration if both Br are facing up? Refer to Q 84 achiever test # 2.

heres a trick, whenever they ask for geometric isomers like Z or E that means you will only have 1 H, if they ask for cis/trans then youll have 2 H's...see how in question 84 they ask which one is not Z/E, all of them except for B have 1 H, B has 2 H's and is considered Cis not Z...

hope that helps...

 

[harrygt]

What will be the splitting pattern for 1,4-dimethylbenzene

I think it should be only 1 singlet. The hydrogens on the ring will not give any splits. The methyl hydrogens give singlet but since both methyl groups are similar (due to symmetry) they will only give 1 singlet right?

I say two singlets. There are two types of H. Why would not the hydrogens on the ring split? They gotta show us a signal.

 

[Mstoothlady2012]

I thought Z means that higher priority groups are on "one side" of the molecule and that is the case with #84 B. If it has 2 H on the same molecule then I can understand why it wouldn't be Z but H are on two different carbon.

 

[osimsDDS]

i meant 2 lone Hydrogens on the molecule...

 

[Mstoothlady2012]

I say two singlets. There are two types of H. Why would not the hydrogens on the ring split? They gotta show us a signal.

Hi after long time 😀

Nvm I just got confused 🙄

 

[harrygt]

Hi after long time 😀

Nvm I just got confused 🙄

Hi I just finished my application today, and turned it in. FINALLY! That is why I was missing from here. lol. I'm back after "long time"!

 

[osimsDDS]

I say two singlets. There are two types of H. Why would not the hydrogens on the ring split? They gotta show us a signal.

I agree its 2 singlets, just draw out the whole thing free hand with the double bonds and carbons and hydrogens...then match up the 2 and 6 carbon and 3 and 5 carbon (im counting starting with the methyl on top attached to the #1 carbon) these 2 will both give 1 signal, then the 2 methyl groups will give 1 singlet for the both because they are equivalent and the carbon they are attached to has no H's so they will give 1 singlet...

So answer is 2 singlets