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188          CHAPTER 7           
 
(b) With a second-order rate equation, the rate is 
expected to be linearly dependent on the concentrations 
of the substrate and the base. If the concentration of the 
base is doubled, then the rate is expected to be two times 
faster. 
(c) With a second-order rate equation, the rate is 
expected to be linearly dependent on the concentrations 
of the substrate and the base. If the concentration of the 
substrate is doubled and the concentration of the base is 
tripled, then the rate is expected to be six times faster 
(×2×3). 
 
7.12. 
(a) We begin by identifying the parent. The longest 
chain is six carbon atoms, so the parent is hexene. There 
is one substituent (highlighted), which is a methyl group. 
 
 
 
With respect to the  bond, the parent could be 
numbered from either direction (either way, the double 
bond will be between C3 and C4), but in this case, we 
must assign numbers from left to right to give the 
substituent the lower possible number (C3 rather than 
C4). We include a locant that identifies the position of 
the double bond (“3” indicates that the double bond is 
located between C3 and C4), as well as a locant to 
identify the position of the substituent. Furthermore, we 
must include the configuration of the double bond (E): 
 
 
 
(b) We begin by identifying the parent, which must 
include the two carbon atoms bearing the double bond. 
The longest possible chain has five carbon atoms, so the 
parent is pentene. There is more than one choice for the 
parent, and we choose the parent with the greater number 
of substituents: 
 
 
There are two substituents (highlighted): a methyl group 
and an ethyl group. The parent is numbered to give the 
double bond the lowest possible number (C2). 
Therefore, the ethyl group is located at C3, and the 
methyl group is located at C4. These groups are 
arranged alphabetically, together with their locants, in 
the name. Finally, we must include the configuration of 
the double bond (E) at the beginning of the name: 
 
 
 
(c) We begin by identifying the parent. The longest 
chain is seven carbon atoms, so the parent is heptene. 
There are three substituents (highlighted), all of which 
are methyl groups. Notice that the parent chain is 
numbered starting from the side that is closest to the  
bond. According to this numbering scheme, the methyl 
groups are located at C2, C3, and C5. Finally, we use 
the prefix “tri” to indicate the presence of three methyl 
groups, and we include a locant that identifies the 
position of the double bond (“2” indicates that the double 
bond is located between C2 and C3): 
 
 
 
Note that the C2 position is connected to two methyl 
groups, so the double bond is not stereoisomeric (neither 
E nor Z). 
 
(d) We begin by identifying the parent. The longest 
chain is seven carbon atoms, so the parent is heptene. 
There are two substituents – a methyl group and an ethyl 
group (highlighted). Notice that the parent chain is 
numbered starting from the side that is closest to the  
bond. According to this numbering scheme, the methyl 
group is located at C2, and the ethyl group is located at 
C3. Finally, we arrange the substituents alphabetically, 
and we include a locant that identifies the position of the 
double bond: 
 
 
 
Note that the C2 position is connected to two methyl 
groups, so the double bond is not stereoisomeric (neither 
E nor Z). 
 
(e) We begin by identifying the parent. The longest 
chain (containing the double bond) is five carbon atoms, 
so the parent is pentene. There are three substituents – 
an isopropyl group and two methyl groups (highlighted). 
Notice that the parent chain is numbered starting from 
the side that is closest to the  bond. According to this 
numbering scheme, the isopropyl group is located at C3, 
and the methyl groups are located at C2 and C4. Finally, 
we arrange the substituents alphabetically, and we 
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