Question

How can you tell from just looking at a condensed formula if a hydrocarbon is linear or branched?

Match the words in the left column to the appropriate blanks in the sentences on the right. Make certain each sentence is complete before submitting your answe

C atoms

−CH3− building blocks

H atoms

one

−CH− building blocks

three

two

−CH2− building blocks

Linear and saturated carbon chains contain, and are extended by, . In each such block, the carbon atom is attached to C atom(s) and H atom(s). When in are replaced by , branches "grow" out of the main chain. When you look at the condensed formula, each such branch is shown in parentheses next to the C atom from which it grows out.

Answer 1

Branched hydrocarbons have branching groups in parenthises in condensed formula. Therefore, in above example part a) which has parenthesis in condensed formula is Branched chain.

The group in parenthesis is the branching group.

Linear and saturated carbon chains contain and are extended by−CH3− building blocks In each such block, the carbon atom is attached to C atom(s) and H atom(s). When H atoms in −CH3− building blocks  

are replaced by C atoms, branches "grow" out of the main chain. When you look at the condensed formula, each such branch is shown in parentheses next to the C atom from which it grows out.