Summary EmSAT Chemistry Notes

 The atmosphere consists of Several layers: lowest is called
troposphere, next is stratosphere (ozone layer is in stratosphere),

 All nucleons remain bound in the dense nucleus because of
strong nuclear force

 To calculate n-p ratio, Bottom number equals protons, top
number is n+p so bottom number-top number= n. Then divide n
by p to get ratio.
 All nuclei outside band of stability are radioactive because the
emit radiation to achieve stability
 The band of stability ends at lead-208. All elements with atomic
numbers greater than 82 are radioactive
 Atoms lying above the band generally have too many neutrons to
be stable while atoms below have too many protons to be stable
 Beta decay DECREASES the number of neutrons
 All nuclei with more than 82 protons are radioactive and decay
spontaneously. These very heavy nuclei often decay by emitting
alpha particles.
 Both neutrons AND protons must be reduced in order to make
radioisotopes stable.
 Beta in reactant= electron capture=B-1
 beta is in reactant side=positron emission=b+1
 Beta in product=beta emission=B-1

 A bond between two identical atoms can never be polar
 Alkane molecules are non polar
 CH bonds have small electronegativity difference
 ALKANE= C#H#+2
 ALKENE=C#H2#
 ALKYNE=C#H2#-2
 Alkenes are more reactive
 Alkynes are generally more reactive than alkenes because the
triple bonds of alkynes have even greater electron density than
the double bonds of alkenes. THIS CLUSTER OF ELECTRONS IS
EFFECTIVE AT INDUCING DIPOLES IN NEARBY MOLECULES,
CAUSING THEM TO BECOME UNEVENLY CHARGED AND THUS
REACTIVE
 Same molecular formula. Different molecular structures: Isomers
 Same formula. Atoms bonded in different arrangement: Structural
Isomers

, Atoms bonded in same order but arranged differently:
stereoisomers
 Different arrangements around a double bond: Geometric
Isomers
 d=dextro=right
 l=levo=left
 Living organisms make use of only one chiral form of a substance
because ONLY this form fits the active site of an enzyme
 Asymmetric carbon= carbon bonded to 4 different atoms or
groups
 Optical isomers= another class of stereoisomers where different
arrangements of four different groups around the same carbon
atom
 Optical isomers have the same physical and chemical properties
except in chemical reactions where chirality is important such as
enzyme-catalyzed reactions in biological systems
 Mirror-image isomers are called optical isomers because they
affect light passing through them
 When polarized light passes through a solution containing an
optical isomer the plane of polarization is rotated to the right
(clockwise, when looking toward the light source) by a d-isomer
or to the left (counter-clockwise) by an l-isomer producing an
effect called optical rotation
 The theory of hybrid orbital predicts that the pairs of electrons
that for the second bond are delocalized and shared among all 6
carbons.
 Delocalization makes benzene chemically stable because
electrons shared by 6 carbon nuclei are hard to pull away.
 Aliphatic= alkanes, alkenes, alkynes
 aromatic= contain benzene rings
 Aromatic compounds react by electrophilic aromatic
substitution reactions, in which the aromaticity of the ring
system is preserved.
 R-X=Halogen, R-OH=Hydroxyl, R-O-R’=Ether, R-NH2=Amino

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 The hydroxyl groups of alcohol molecules are moderately polar
and are able to form hydrogen bonds with the hydroxyl groups of
other alcohol molecules. Due to this hydrogen bonding, alcohols
have much higher boiling points than hydrocarbons of similar
shape and size.
 Ethanol is completely miscible with water
 Aerobic= 1 mol glucose= 38 mol of atp
 Anaerobic=1 mol glucose=2 mol atp
 Common types of fermentation= production of ethanol and
carbon dioxide, production of lactic acid
 Alcoholic fermentation: Glucose> Ethanol+co2+energy
 Aldehyde name= changing the “e” from the name of the alkane
to “aldehyde”