what is the correct structure for 2-ethyl-butane?
Is this correct?
CH3-CH2-CH2-CH3
Underneath the the first ch2 they should be ch3 underneath it/
correct.
oops.
No, what you have proposed with the CH3 below is 2-methylbutane EXCEPT that you have a 5-valent C on C2. If you want 2-ethylbutane you want a CH3CH2 (or C2H5) below the second CH2. But when you attach the C2H5 group you must remove one of the H atoms.
You can write it this way.
CH3CH(C2H5)CH2CH3
I agree with DrBob, I was too hasty.
The correct structure for 2-ethylbutane is CH3-CH2-CH(CH3)-CH2-CH3.
To determine the correct structure, you need to follow a few steps:
1. Start by identifying the main carbon chain, which consists of four carbon atoms in this case (butane).
2. Next, locate the 2-ethyl group. The "2-ethyl" indicates that the substituent (ethyl group) is attached to the second carbon atom of the main chain.
3. To place the ethyl group correctly, replace one of the hydrogen atoms on the second carbon atom of the main chain (CH2) with the ethyl group (CH3-CH2-).
4. Finally, add the remaining carbon atoms and hydrogen atoms to complete the structure. The correct structure for 2-ethylbutane is CH3-CH2-CH(CH3)-CH2-CH3.
So, underneath the CH2 in the second carbon atom, there should be CH3 attached to it, indicating the ethyl group substitution.