Which of the following is the correct dash formula for `n`-propyl alocohol?

Options

A. (1) (i)
B. (2) (i), (ii)
C. (3) (i), (iv)
D. (4) (i), (ii), (iii), (iv)

Answer

D

Explanation

The atoms joined bu single bonds can rotate relatively freely with respect to one another. This relative free rotation means that the chain of atoms in propyl alcohol can assume a variety of arrangements. Thus, all of the dah structures above are equivalent and all represent propyl alcohol.
Notice that in these formulas, we represent the bond angles as being `90^(@)` and not `109.5^(@)`. This convention is followed simply for convenience in printing. Sometimes we omit unshared electron pairs when we write dash formulas.