CHEM 219: MODULE 2 EXAM

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CHEM 219: MODULE 2 EXAM

QUESTIONS WITH 100% CORRECT

ANSWERS

Question : list prefixes for first 10 carbons in order

CORRECT ANSWER : meth, eth, prop, but, pent, hex,

hept, oct, non, dec

Question : hydrocarbon

CORRECT ANSWER : compounds composed of only

carbon and hydrogen

Question : parent chain

CORRECT ANSWER : longest continuous chain of

carbon atoms

Question : substituent

CORRECT ANSWER : heteroatom or group of atoms

that are attached to the parent chain

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Question : numerical prefixes for # of identical

substituent groups (2-10 in order)

CORRECT ANSWER : di, tri, tetra, penta, hexa, hepta,

octa, nona, deca

Question : alkane (with formula)

CORRECT ANSWER : hydrocarbon containing only

single bonds between carbons, CnH2n+2

Question : rules for naming alkanes

CORRECT ANSWER : 1. longest continues chain is

parent chain

• number parent chain starting with the end closest to the

first branch

• name using IUPAC rules for substituents

Question : IUPAC systematic name order for alkanes

CORRECT ANSWER : locant-(prefix)SubstituentParent

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Question : in numbering parent chains, if there are two

equally long chains...

CORRECT ANSWER : select the chain with the most

branches coming off

Question : in numbering parent chains, if the first branch

point if the same distance from either end of the parent chain...

CORRECT ANSWER : choose the numbering that gives

the lower numbers to the most substituents

Question : in numbering parent chains, if there are only 2

substituents and both are equidistant from opposite ends of the parens chain...

CORRECT ANSWER : choose the numbering direction

so the substituent with the higher alphabetical priority gets the lower locant number

Question : solubility and density properties of alkanes

CORRECT ANSWER : NOT soluble in water, low

density (< 1g/ml) so floats on top of water

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Question : melting and boiling points properties of

alkanes

CORRECT ANSWER : LOW MPs and BPs due to weak

attractive forces between molecules

Question : how does branching affect MPs and BPs

CORRECT ANSWER : branching lowers surface area of

the molecule, which in turn lowers VDWFs and thus lowering BPs and MPs

Question : conformers

CORRECT ANSWER : different shapes of molecules

derived from rotations of single bonds

Question : staggered conformation

CORRECT ANSWER : H atoms do not overlap in line

of sight (more stable)

Question : eclipsed conformation