Question

What is the best name for the molecule below? a compound with 10 total carbons with a double bond and the rest single bonds. there is a straight chain of seven carbons along the bottom with a double bond between the third and fourth carbons when counting from left to right. there is a propyl group branching off of the fifth carbon from the left. 5-propyl-3-heptene 5-ethyl-3-octene 3-ethyl-5-octene 3-ethyl-4-heptene?

Answer 1

The correct answer is 5-propyl-3-heptene. 

Answer 2

Answer:

5-propyl-3-heptene

Explanation:

There is a straight chain of seven carbons along the bottom with a double bond between the third and fourth carbons when counting from left to right.

1  2   3  4  5  6  7

C-C-C=C-C-C-C

There is a propyl group branching off of the fifth carbon from the left.

1  2   3  4  5  6  7

C-C-C=C-C-C-C

                 |

                 C₃H₇

Th final structure is:

1        2      3    4     5      6       7

H₃C-CH₂-CH=CH-CH₂-CH₂-CH  ₃

                              |

                              C₃H₇

The  best name for the molecule is:

5-propyl-3-heptene

The side chain propyl is at the 5th C atom. Also the third bond from the left is a double bond. A seven C main chain is called heptane if there is no double bond. Since there is one double bond in the main chain it is named heptene.