Please Help Quick! Chemistry help needed...?

Question

1)Draw the condensed structural formula for 3,3-diethyl-2,5-dimethylnonane.

2) Draw the condensed sructural formulas for the two structural isomers of methylpentane and name the isomers.

---Any help would be extremely helpful. I do not understand at all so if possible, show the drawings and then explain how you got them. Thank you soo much!

Answer 1

To start off,  you have nonane

CH3CH2CH2CH2CH2CH2CH2CH2CH3

1     2    3     4    5     6    7    ...

Then you have some substituents

3,3-diethyl.  Start counting from one end

CH3CH2C(C2H5)2CH2CH2CH2CH2CH2CH3

1     2    3             4    5    6  ...

2,5-dimethyl

CH3CH(CH3)C(C2H5)2CH2CH(CH3)CH2CH2CH2C...

1     2           3             4   5 ...

Note that when you add an alkyl substituent,  you remove a hydrogen

Then methylpentane

First Pentane

CH3CH2CH2CH2CH3

1     2     3    4     5

Then you need to add a methyl group

There can be 2 methylpentane

CH3CH(CH3)CH2CH2CH3

1    2            3    4     5

And 3-methylpentane

CH3CH2CH(CH3)CH2CH3

1     2    3            4    5

Why can't there be others?

Well if you tried to put a methyl group on the 1 or 5 position,  the longest chain would be six carbons long and would be a hexane.

If you put the methyl group on the 4 position,  it is the same compound as if you put it in the 2 position.

Note that I have put the substituents off the main chain in parentheses for clarity.   Some methods of writing the compounds would not put in these parentheses.

Answer 2

well what i would do is ask someone that knows about chemistry. i'm in chemistry to and i'm having difficulties 2. But 2 me chemistry is sort of like math to me the reason i say that is because you have alot more thinking 2 do and that makes your brain hurt

Answer 3

Nonane is an alkane with 9 Carbon atoms, so its formula will be C9H20, and condensed one CH3(CH2)7CH3. To this you have to add 2 methyl groups: one at the 2nd and one at the 5th Carbon, so the molecule will become CH3CHCH3(CH2)2CHCH3(CH2)3CH3. Than you have to add 2 ethyl groups both at the 3rd Carbon. The final molecule will be: CH3CHCH3CH(CH2CH3)2CH2CHCH3(CH2)3CH3.

The 2 isomers of methylpentane instead are 2-methylpentane and 3-methylpentane (there is no 1-methylpentane because its structure would be exactly the same of hexane. There is no 4-methylpentane because it would be the same as 2-methylpentane).

Pentane structure is CH3(CH2)3CH3 and you have to add a methyl group at the 2nd Carbon for 2-methylpentane and at the 3rd Carbon for 3-methylpentane.

2-methylpentane: CH3CHCH3(CH2)2CH3

3-methylpentane: CH3CH2CHCH3CH2CH3