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A.

Select the correct structure that
corresponds to the name.
heptane
B.
CH3(CH2)4CH3

A. Select the correct structure that corresponds to the name. heptane B. CH3(CH2)4CH-example-1

1 Answer

3 votes

Answer:

Only A., the stick structure with no branches and five vertices between the two endpoints.

Step-by-step explanation:

An alkane is a saturated hydrocarbon compound with no branches- just a series of carbon atoms connected with
{\rm C}-{\rm C} single bonds. Heptane is the name for an alkane with
7 carbon atoms (the prefix "
\verb!hept-!" means "seven".)

Notice that there are only
6 carbon atoms in the alkane with the condensed structure formula
{\rm CH_(3)}({\rm CH_(2))_(4){\rm CH_(3)}. The name for that structure would be hexane, not heptane.

In general, the condensed structure formula of an alkane with
n carbon atoms (
n > 2) is
{\rm CH_(3)}({\rm CH_(2)})_(n-2) {\rm CH_(3)}. The correct condensed structure formula for heptane (
n = 7) would be
{\rm CH_(3)}({\rm CH_(2)})_(5) {\rm CH_(3)}.

The structure in choice A is represented as a line-angle formula. As long as no letter is present in the formula, each vertex in the line-angle formula (including the endpoints) represents a carbon atom. Hence, the line-angle formula in choice A would represent a hydrocarbon with
7 carbon atoms.

A single line denotes a single bond between atoms. All
7 carbon atoms in this structure are thus joined in a line with
{\rm C}-{\rm C} single bonds. Hence, this structure denotes an alkane with
7 carbon atoms- heptane.

User Bajrang Hudda
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