alkanes, cycloalkanes & alkyl halides

Question 1

How do non polar molecules dissolve? what type of density do they have?

Answer 1

Non-polar molecules: dissolve in non-polar or weakly polar organic solvents and are
hydrophobic
Less dense than water and insoluble in water

Question 2

How does bond rotation differ?

Answer 2

*bond rotation occurs in single bonds only
*double bonds do not have rotation
*each structure generated by rotation has either conformer or conformational isomers

Question 3

What bonds do we draw + what type of bonds do these bonds contain?

Answer 3

draw the lowest-energy conformation: the one with
minimal electrostatic repulsion between bonds
+most conformations have staggered bonds

Question 4

What are the two types of ways that bonds are drawn? H-C-C-H only

Answer 4

*eclipsed
*staggered

Question 5

What are the more complex names of structure (methyl groups)?

Answer 5

*gauche
*opposed
*anti
*syn-periplanar
*synclinal
*anticlinal
*anti-periplanar

Question 6

What are the two faces of a cycloalkane?

Answer 6

two substituents point to the same face: cis
two substituent point towards opposite face: trans

Question 7

What can cycloalkanes experience?

Answer 7

These may experience angle strain and torsional strain = ring strain

Question 8

how can ring strain be prevented?

Answer 8

strain can be reduced by deviating from a planar structure

Question 9

What would happen to a flat cyclohexane + how to fix this?

Answer 9

*angle strain and *torsional strain if flat
can be fixed by: chair conformation = all angles 109.5° and all H staggered

Question 10

What can cyclohexane do + types of chair conformations?

Answer 10

*cyclohexane can flip between chair conformations
*chair
*half-chair
*boat
*twist-boat

Question 11

Substituents on cyclohexane preference?

Answer 11

*substituents prefer to be equatorial rather than axial
*larger substituents give a greater preference for the equatorial position

Question 12

What are the types of halide?

Answer 12

*alkyl halide
*vinyl halide
*aryl halide

Question 13

What are the steps to understand alkane nomenclature?

Answer 13

1. Find the longest continuous chain of carbon atoms, and use this chain
   as the base name (parent, i.e. CH4 methane, CH3CH3 ethane…). An
   indicate presence of alkane (no carbon) double or triple bonds
2. Number the longest chain, beginning with the end nearest a branch
3. Name the substituents on the longest chain as alkyl groups (i.e. CH3-
   methyl, CH3CH2- ethyl…) and give the location on main-chain carbon atom
4. Two or more substituents present, list them in alphabetical order. Two or
   more of the same alkyl substituent, use the prefixes di-, tri-, etc.

Question 14

What to do to understand cycloalkane nomenclature?

Answer 14

Substituted cycloalkanes: cycloalkane form the parent (with cyclo), with the
alkyl groups named as substituents of the cycle
Two or more substituents attached to the cycle: carbons are numbered to give
the lowest possible numbers for the substituted carbons and continues in the
direction that gives the lowest possible numbers to the other substituents
Numbering begin with the carbon that has more substituents; otherwise,
begin with the carbon that is first alphabetically
Acyclic portion more carbon atoms or important functional group: the cyclic
portion is named as a cycloalkyl substituent