Chapter 9 Flashcards
Alkynes are hydrocarbons that contain C-C triple bonds are also called _______
acetylenes
What is the general formula for alkynes (given C and H)
CnH(2n-2)
While naming alkynes, the suffix used is _______
yne
If both alkenes and alkynes are in the same molecule the term ________ is used
enyne
When an enyne is present, give the lowest possible numbers to the pi bonds. IF numbering is equal, the _______ takes priority
alkene
physical property of alkynes:
1) they are _______, insoluble in water
2) boiling points of alkynes _______ if the molecular weight increases
3) alkynes are _______ dense than water
4) if there are __ carbons then it is a gas at room temp
1) nonpolar
2) increase
3) less
4) 4
triple bonds are ______ in length than C=C and C-C
shorter
individual bonds in a triple bond are _______ than individual bonds in a double bond
weaker
The most common base used to deprotonate an alkyne is _______
sodium amide (NaNH2)
in order to deprotonate an alkyne, the base must have a _______ pKa
higher
List the order of the pKa table 1(greatest)-5(least)
1) alkane
2) alkene
3) amide
4) alkyne
5) alcohols
During the alkylation of acetylide ions, if the electrophile is primary or a methyl halide then the reaction is _______
Sn2
During the alkylation of acetylide ions, if the electrophile is secondary or a tertiary halide then the reaction is _______
E2
When adding acetylide ions to carbonyl groups, the intermediate containing the single bond O- is called the _______
tetrahedral intermediate
During the synthesis of alkynes from a dihalide, harsh conditions are required. What are the 2 conditions?
1) KOH and heat
2) NaNH2 and heat
