what is the structural formula for 4-ethyl- 22- dimethyl heptane?

Answer 1

Heptane is a 7 carbon chain with no double bonds. You can start counting from either end. On carbon 4 there is an thyl group(CH3CH2) . It is impossible to have a carbon 22. If it was 2, then there would be 2 methyl groups on carbon 2.(CH3). All carbons must have 4 bonds and can have no more, so add H to each carbon in the chain where there are not other bonds.(It is only the C's that can bond to each other)

H-CH2-C(CH3)2 -CH2-CH(CH3CH2)- CH2-CH2-CH3

Counting from the left, carbon2 has the 2 methyl groups, carbon 4 has the ethyl group.

Answer 2

22-dimethyl ..?...I guess you mean 2-methyl.

CH3-C(CH3)2-CH2-CH(C2H5)-CH2-CH2-CH3.

Saturated, single bonds.
2nd C has 2 methyl group branches.
4th C has the ethyl group branch.
C7H13(C2H5)(CH3)2 ..C11H24..4-ethyl-2-dimethyl heptane.

(Note: the H2 of the 6th C,.. ,and the last CH3 have not come in when submitted).

Answer 3

first, draw a heptane chain.

CH3-CH2-CH2-CH2-CH2-CH2-CH3 (assuming n-heptane)

now starting from the left, we have an ethyl group on the 4th carbon atom, and 2 methyl groups on the 2nd carbon atom.
that gives

CH3-CH(CH3)2-CH2-CH2(C2H5)-CH2-CH2-CH3

Answer 4

Shaun is almost right. Drawing it his way,

CH3-C(CH3)2-CH2-CH(CH2CH3)-CH2-CH2-CH3

This structure avoids having 5 bonds to carbon-2.

Answer 5

see it here --- http://lb.chemie.uni-hamburg.de/static/data/18_g47plvaf.html

Answer 6

...........CH3 ............ \ CH3CH2-C-CH2CH2CH3 ............. |... \ .............CH3..CH2CH3