Term
| valence shell electron pair repulsion (VSEPR)theory is based on what? |
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Definition
| the simple idea that electron groups, which we define as lone pairs, single bonds, multiple bonds, and even single electrons, repel one another through coulombic forces. Repulsions between electron groups determine molecuular geometry. |
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Term
| which occupies more space, a bonding pair or a nonbonding pair of electrons? |
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Definition
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Term
| tetrahedral geometry is like how many balloons tied together? |
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Definition
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Term
| five electron groups around a central atom assume a ______ bipyramidal geometry |
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Definition
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Term
| six electron groups around a central atom assume a ________ geometry, like that of _____ balloons together |
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Definition
| octahedral geometry; six balloons |
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Term
| in a five electron group with lone pairs, is the axial or the equatorial position more favorable for lone pair electrons? why? |
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Definition
| the equatorial position; because it has only 2 90 degree interactions with bonding pairs. |
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Term
| what 5 things count as a single electron group? |
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Definition
| a lone pair, a single bond, a double bond, a triple bond, or a single electron |
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Term
| all ______ ______ on the central atom determine the shape of a molecule according to the VSEPR theory |
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Definition
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Term
| what degree do three bonding pairs have between them? |
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Definition
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Term
| how many degrees between hydrogen would CH4 assume, since it has no lone pairs? |
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Definition
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Term
| ____ lone pair(s) is = to 107 degrees in NH3 |
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Definition
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Term
| 109.5 degree is ideal for how many lone pairs in tetrahedral geometry? (water, for instance) |
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Definition
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Term
| what would the geometry look like of an element with five electron GROUPS? what are the angles? |
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Definition
| a trigonal bypyramid one on top, one on bottom, three around axis; 90 degrees from the top or bottom to the axial groups, and 120 degrees for in between the axial groups |
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Term
| what does tetrahedral geometry look like? how many electron groups is this? |
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Definition
| a molecule with four or more electron groups would have tetrahedral geometry; there is one group at the top of the central atom, and three groups that are at 109.5 degree angles around the axis in the lower portion |
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Term
| what kind of geometry would six electron groups make? what would it look like? what is the degree in between all of the balloons |
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Definition
| octahedral geometry. it would have one group on top, one on bottom, and four around the central axis; 90 degrees |
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Term
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Definition
| valence shell electron pair repulsion |
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Term
| two lone pairs in H20 would be what degree for the ACTUAL molecular geometry? |
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Definition
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Term
| in SF4 it creates what molecular geometry? (because of the equatorial lone pair, it has 5 electron groups) |
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Definition
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Term
| in BrF3, two of the five electron groups around the central atom are lone pairs. what positions would the lone pairs occupy and why? what is the electron geometry of this structure and what is the molecular geometry? |
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Definition
| they are in the equatorial positions. this minimizes 90 degree interactions. the electron geometry is trigonal bipyramidal and the molecular geometry is T-shaped |
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Term
| in BrF5 there are six electron groups because of a lone pair. what is the electron geometry and the molecular geometry? |
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Definition
| the electron geometry is octahedral, and the molecular geometry is square pyramidal |
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Term
| when two of the six electron groups around the central atom are lone pairs, what positions do the lone pairs occupy? what is the electron & molecular geometry? |
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Definition
| the occupy the axial positions. electron geometry is octahedral and molecular geometry is square planar |
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Term
| three electron groups around a central atom is what electron & molecular geometries? |
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Definition
| trigonal planar, trigonal planar |
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Term
| is a molecule polar or nonpolar if 2 polar bonds are "bent"? |
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Definition
| polar- you iextend a vector between them |
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Term
| is a molecule nonpolar or polar if it has three identical polar bonds at 120 degrees from each other? |
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Definition
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Term
| if the dipole moments of four identical polar bonds in a tetrahedral arrangement cancel, is it polar or nonpolar? |
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Definition
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Term
| the dipole moments of three polar bonds in a trigonal pyramidal arrangement (109.5 degrees from eachother) will cancel or not cancel? therefore it is, polar or nonpolar? |
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Definition
| they will not cancel and result in a dipole moment vector. it is polar. |
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Term
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Definition
| a measure of the separation of positive and negative charge in a molecule |
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Term
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Definition
| the ability of an atom to attract electrons to itself in a COVALENT BOND |
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Term
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Definition
| the sum of the internal energy of a system and the product of its pressure and volume; the energy associated with the breaking and forming of bonds in a chemical reaction |
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Term
| arrange the electron group repulsions from order of greatest to smallest lonepair/bonding pair, bonding pair/bonding pair, lone pair/lone pair |
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Definition
| lone pair/lone pair > lone pair/bonding pair > bonding pair/bonding pair |
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Term
| what are the 3 steps in determining if a molecule is polar? |
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Definition
1) Draw a Lewis structure for the molecule and determine the molecular geometry
2) determine whether the molecule contains polar bonds
3) determine whether the polar bonds add together to form a net dipole moment |
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Term
| why do oil and water not mix? |
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Definition
| water is polar, so its molecules interact strongly with one another and clump together |
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Term
| is OH polar or nonpolar? will it attract water? |
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Definition
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Term
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Definition
| an advanced model of chemical bonding in which electrons reside in quantum-mechanical orbitals localized on individual atoms that are a hybridized blend of standard atomic orbitals; chemical bonds result from an overlap of these orbitals |
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Term
| the interaction energy is usually ________ (or stablizing) when the interacting atomic orbitals contain a total of two electrons that can spin-pair. what theory does this come from? |
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Definition
| negative energy; valence bond theory |
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Term
| a chemical bond result from the overlap of what? what kind of pairing do they do? what is the less common kind of overlap? |
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Definition
| a chemical bond result from the overlap of two HALF FILLED ORBITALS with SPIN PAIRING of the two valence electrons (or less commonly the overlap of a completely filled orbital with an empty orbital) |
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Term
| what is a covalent chemical bond according to Lewis theory? |
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Definition
| the sharing of electrons (represented by dots) |
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Term
| what is a covalent chemical bond according to valence bond theory? |
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Definition
| the overlap of half-filled atomic orbitals |
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Term
| what does hybridization in the valence bond theory recognize? |
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Definition
| that the orbitals in a molecule are not necessarily the same as the orbitals in an atom |
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Term
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Definition
| orbitals formed from the combination of standard atomic orbitals that correspond more closely to the actual distribution of electrons in a chemically bonded atom |
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Term
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Definition
| a mathematical procedure in which standard atomic orbitals are combined to form new, hybrid orbitals |
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Term
| hybrid orbitals (minimize/maximize) the orbital overlap in a bond. this (minimizes/maximizes) the energy of the molecule. |
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Definition
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Term
| a greater overlap in a molecule means (stronger/weaker) bonds |
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Definition
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Term
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Definition
| held together by metallic bonding. Metals tend to lose electrons to form cations. These lost electrons form what is known as a "sea of electrons" to which the positively charged cations are attracted. |
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Term
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Definition
| are substances made up of covalent molecules that are cold enough to be frozen. Ice is an example of a molecular solid. |
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Term
| covalent (network) solids |
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Definition
| substances made up of atoms held together by interconnecting covalent bonds. Quartz is an example. |
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Term
| what is the electronic geometry of H20? |
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Definition
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Term
| the electronic geometry of a molecule with 5 electron groups is called |
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Definition
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Term
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Definition
| when p orbitals overlap side by side |
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Term
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Definition
| when orbitals overlap end to end |
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Term
| a single bond is a ______ bond |
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Definition
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Term
| a double bond is a _____ and a ___ bond |
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Definition
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Term
| triple bond consists of a ____ bond and two ____ bonds |
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Definition
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Term
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Definition
| compound with the same molecular formula but different structures or different spatial arrangement of atoms |
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Term
| sp hybridization is what electron geometry? |
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Definition
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Term
| trigonal planar (3 groups) is what hybridization? |
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Definition
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Term
| sp3 is linear, trigonal planar or tetrahedral? |
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Definition
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Term
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Definition
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Term
| an octahedral electron geometry is what hybridization? |
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Definition
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Term
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Definition
| an advanced model of chemical bonding in which the electrons reside in molecular orbitals delocalized over the entire molecule. In the simplest version, the molecular orbitals are simply linear combinations of atomic orbitals. |
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Term
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Definition
| a molecular orbital that is lower in energy than any of the atomic orbitals from which it was formed |
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Term
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Definition
| a molecular orbital that is higher in energy than any of the atomic orbitals from which it was formed |
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Term
| does the bonding molecular orbital arise from constructive or destructive interference? |
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Definition
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Term
| destructive interference between the atomic orbitals results in what molecular orbital? |
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Definition
| antibonding molecular orbital |
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Term
| bonding orbitals have increased electronic density in the internuclear region, with a greater/lesser energy than nonbonded atoms |
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Definition
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Term
| is the energy in antibonding orbitals higher or lower than in the orbitals of nonbonded atoms? why? |
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Definition
| the energy is higher, because the electron density in the internuclear region is lower |
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Term
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Definition
(# of electrons in bonding MOs)-(#of electrons in antibonding MOs),
divided by 2 |
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Term
| a + bonding order implies that the molecule is stable/unstable |
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Definition
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Term
| the higher the bond order, the stronger/weaker the bond |
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Definition
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Term
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Definition
| attracted to an external magnetic field because of unpaired electrons. |
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Term
| the more electronegative an element, the lower/higher the energy in the atomic orbitals |
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Definition
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Term
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Definition
| an orbitals whose electrons remain localized on an atom |
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Term
| if the bond order is 0, does the molecule exist? |
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Definition
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Term
| when finding the hybridization, a double bond counts for how many charge clouds? |
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Definition
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