Ochem Canvas HW
When two groups are on the opposite side (face) of a cycloalkane, they are described by the following term ________________ .
trans
Neutral carbon takes part in __[A]__ bond(s) and has __[B]__ nonbonded pairs of electrons.
4, 0
Equivalent resonance contributing structures make equal contributions to the resonance hybrid.
True
For a reaction to occur, it must have both "motive" (thermodynamic driving force) and "opportunity" (a relatively low overall energy barrier to reaction).
True
For organic chemistry, it is best to think of electron density as waves, described by wave equations.
True
For unequal resonance contributing structures: full octets are favored, more covalent bonds are favored, fewer charges are favored, and a negative charge on more electronegative atom (also positive charge on less electronegative atom) are favored.
True
Hyperconjugation is due to the overlap of an empty 2p orbital of a carbocation with adjacent sigma bonding electron density.
True
Reactions have a "motive" (thermodynamic driving force) if the products are lower in energy than the starting materials.
True
Reactions will go faster if they have a lower energy barrier.
True
Resonance contributing structures are used when more than one structure are required to describe accurately how the electrons and charges are distributed in a molecule
True
Resonance contributing structures do not represent equilibrating structures, rather the hybrid (blending) of them is the true molecular representation.
True
When drawing resonance contributing structures, you should move pi bonds (one bond of a double or triple bond) and lone pair electrons, not atom nuclei or sigma bonds.
True
When two groups are on the same side (face) of a cycloalkane, they are described by the following term ______________ .
cis
Three (or more) atom "pi-ways" are the situation resonance ___________structures are usually trying to describe. For pi bonding and therefore pi delocalization to occur over more than two atoms (i.e. pi-ways), parallel and overlapping 2p orbitals are needed on ALL of the adjacent atoms involved. As a result, all of the atoms involved in pi-ways are usually _____________ hybridized, and NEVER sp3 hybridized.
contributing, sp2
A Carbon atom with 0 nonbonded pairs of electrons and 3 bonds has a _____ formal charge.
+1
A Chlorine atom with 4 nonbonded pairs of electrons and 0 bonds has a ____ formal charge.
-1
The two important consequences of the pi bond in alkenes is that:
-electron density is above and below the bond axis, so it is available to react with electron deficient species (called electrophiles) -the double bond cannot rotate
Neutral oxygen takes part in __[A]__ bond(s) and has __[B]__ nonbonded pairs of electrons.
2, 2
Large groups on cyclohexane molecules prefer to be____________ primarily because of ______________ strain. Another name for this kind of strain is a(n) _____________ interaction.
Equatorial, Steric, diaxial
A pi bond occurs when the majority of the electron density is found on the bond axis.
False
An sp3 hybridized carbon atom has only one major hybridized orbital.
False
An sp3 hybridized carbon atom has only two major hybridized orbitals, arranged in a bent geometry.
False
For organic chemistry, it is best to think of electron density as particles, described by Newton's laws.
False
Hyperconjugation is due to the overlap of electronegative elements with empty 2p orbitals in pi bonds.
False
Reactions always go faster if the products are lower in energy than the starting materials.
False
Reactions will always have a "motive" (thermodynamic driving force) if they have a lower energy barrier.
False
When drawing resonance contributing structures you generally move atom nuclei and sigma bonds.
False
Cyclobutane has considerably more _____ and _____ strain compared to cyclohexane.
Torsional and Angle
Cyclobutane is puckered to minimize _____ and _____ strain.
Torsional and Angle
Fill in the blanks with the words that best complete the following sentences. ______________strain is the term used to explain that eclipsed conformations of ethane are less stable than staggered conformations. For butane, the most stable conformation is the staggered, anti conformation because this conformation minimizes _________________strain between the methyl groups.
Torsional, steric
A sigma bond occurs when the majority of the electron density is found on the bond axis.
True
An sp2 hybridized carbon atom has three hybridized orbitals, arranged in a trigonal planar geometry.
True
An sp3 hybridized carbon atom has four hybridized orbitals, arranged in a tetrahedral geometry.
True
An sp3 hybridized carbon atom has four major hybridized orbitals, arranged in a tetrahedral geometry.
True
