Ignore the dots, just put them in to line things up.
1. What is the asymmetric carbon
5...4...3..2..1
CH3-CH2-CH-CH-CH3
........|..|
CH3.CH3
2. which of the following compounds have an asymmetric carbon?
A. CH3-CH-CH-CH3
........|..|
........OH.CH3
B. CH3-CH-CH3
........|
........CH3
C. CH3-CH-F
........|
........OH
The asymmetric carbon for the first one is #3 by your numbering system.
The periods don't help that much but I can guess where the substituents go from the number of H atoms attached for the second question.
A has an asymmetric carbon on #2 (first C on left is #1), B has none, and C has one on #2 carbon (first C on left is #1).
Check my thinking.
To determine the presence of an asymmetric carbon, we need to look for a carbon atom that is attached to four different groups. In the given structure:
CH3-CH2-CH-CH-CH3
........|..|
.......CH3.CH3
We can identify the central carbon atom (marked with "-") as an asymmetric carbon. This is because it is attached to four different groups - two methyl (CH3) groups, an ethyl (CH2CH3) group, and a hydrogen (H) atom.
Now, let's analyze the compounds given in options A, B, and C to identify if they have an asymmetric carbon.
A. CH3-CH-CH-CH3
........|..|
........OH.CH3
In option A, we can observe that the carbon atom marked with "-" is attached to three methyl (CH3) groups and an hydroxyl (OH) group. Since it is not attached to four different groups, option A does not have an asymmetric carbon.
B. CH3-CH-CH3
........|
........CH3
In option B, we can see that the carbon atom marked with "-" is attached to three methyl (CH3) groups. Similar to option A, it is not attached to four different groups, so option B does not have an asymmetric carbon either.
C. CH3-CH-F
........|
........OH
In option C, the carbon atom marked with "-" is attached to a methyl (CH3) group, a fluorine (F) atom, and an hydroxyl (OH) group. Since it is attached to four different groups, option C has an asymmetric carbon.
Therefore, the compound in option C, CH3-CH-F, has an asymmetric carbon.