Chapter 2

Question 1

Hydrocarbon

Answer 1

compound composed of only C and H

Question 2

saturated hydrocarbon

Answer 2

single bonds only (ex: alkane)

Question 3

unsaturated hydrocarbon

Answer 3

contains double or triple bonds (alkenes, alkynes, arenas)

Question 4

line structure formula

Answer 4

1. carbon atoms @ each corner
2. draw bonds between corners
3. don’t show H’s on Carbons
4. show other atoms

Question 5

Constitutional Isomers

Answer 5

compounds with same molecular formula, but different connectivity of atoms

Question 6

how to determine if compounds are constitutional isomers

Answer 6

1. write the molecular formula for each
2. Find the longest carbon chain
3. # each chain from the end nearest the first branch
4. compare chain lengths + the identity and location of branches

Question 7

nomenclature and IUPAC

Answer 7

Parent name: longest carbon chain

substituent: group bonded to parent

Question 8

IUPAC nomenclature rules

Answer 8

1. identify the longest carbon chain parent)
2. # the chain to give the substituent the lower
3. identical substituents: lower # to the first substituent (# of times substituent occurs - give prefix di, tri, tetra, penta, hexa, etc)
4. different substituents & numbering gives a ties:lower number based on alphabetical order (prefixes are not included in alphabetizing)
5. multiple parent chains of identical length: number the one with greater substituents

Question 9

infix

Answer 9

nature of C-C bond (single, double, triple)

Question 10

torsional strain

Answer 10

strain that arises when going from one conformation to another

Question 11

anti conformation

Answer 11

groups on adjacent carbons are 180 degree dihedral angle

Question 12

gauche conformation

Answer 12

groups on adjacent carbons are at a 60 degree dihedral angle

Question 13

causes of torsional strain

Answer 13

• angle strain: bond angle is smaller or larger than optimal value
• steric strain: (non bonded interaction strain) forcing non bonded atoms close to each other

Question 14

general formula for cycloalkanes

Answer 14

C(n)H(2n)

Question 15

naming rules for cycloalkanes

Answer 15

1. add prefix cycle
2. if one substituent, no #
3. if two substituents, # alphabetically
4. if three + substituents, lowers set of numbers then alphabetically

Question 16

bicycloalkanes

Answer 16

two rings that share two carbons

Question 17

strain

Answer 17

measure of energy stored in a compound due to structural distortion

Question 18

conformation

Answer 18

any 3D arrangement of atoms in a molecule that results from a rotation about a single bond

Question 19

dihedral angle

Answer 19

angle created by two intersecting planes, as defined by 3 atoms

Question 20

small ring strain

Answer 20

exists for rings <6 carbons

Question 21

stereoisomers

Answer 21

compounds that have the same molecular formula, connectivity of atoms, but different orientation of atoms in space

Question 22

cis

Answer 22

same side

Question 23

trans

Answer 23

opposite sides

Question 24

dispersion forces

Answer 24

weak intermolecular forces of attraction resulting from the interaction between temporary induced dipoles
increase: melting and boiling point increase

Question 25

alkanes

Answer 25

major sources: fossil fuels - natural gas, petroleum, coal
-80% of total energy consumed
bulk of raw materials used to make organic materials