Chapter 10: Sections 1-4 Flashcards
Taste and caloric value are __________ properties of food.
Independent
The caloric value of a food depends on the amount of __________ released when the food is metabolized.
Energy
The caloric value of a food depends on the amount of energy released when the food is __________.
Metabolized
The taste of a food is __________ of its metabolism.
Independent
The sensation of taste originates in the tongue, where specialized cels called taste cells act as highly sensitive and specific __________ __________.
Molecular detectors
These cells can discern sugar molecules from the thousands of different types of molecules present in a mouthful of food.
Taste cells
The main factors for the discrimination of sugar molecules from other molecules present in a mouthful of food are the molecule’s __________ and __________ __________.
Shape, charge distribution
The surface of a taste cell contains specialized protein molecules called:
Taste receptors
A molecule that we can taste.
Tastant
A particular tastant fits snugly into a special pocket on the taste receptor protein called the:
Active site
These all depend on shape-specific interactions between molecules and proteins.
Immune response, the sense of smell, and many types of drug action
The valence bond theory and the molecular orbital theory are _____ complex and _____ powerful than Lewis theory.
More, more
Allows prediction of the shapes of molecules based on the idea that electrons- either as lone pairs or as bonding pairs- repel one another.
Valence shell electron pair repulsion theory (VSEPR theory)
A general term for lone pairs, single bonds, multiple bonds, or lone electrons in a molecule.
Electron groups
The VSEPR theory is based on the idea that electron groups repel one another through __________ forces.
Coulombic
According to VSEPR theory, the repulsion a between electron groups on __________ __________ of a molecule determine the geometry of the molecule.
Interior atoms
According to VSEPR theory, the repulsion a between electron groups on interior atoms of a molecule determine the __________ of the molecule.
Geometry
The preferred geometry of a molecule is the one in which the electron groups have the __________ separation possible.
Maximum
The preferred geometry of a molecule is the one in which the electron groups have the maximum separation (and therefore the __________ energy) possible.
Minimum
The interior atom is also referred to as the:
Central atom
For molecules having just one interior atom, molecular geometry depends on these two things:
1) The number of electron groups around the central atom
2) How many of those electron groups are bonding pairs and how many are lone pairs
Two electron groups = __________ geometry.
Linear
The molecular geometry of three atoms with a 180 degree bond angle due to the repulsion of two electron groups.
Linear geometry
The basic idea of VSEPR theory is that repulsions between electron groups determine __________ __________.
Molecular geometry
Molecules that form only 2 single bonds, with no lone pairs, are rare because they do not:
Follow the octet rule
Three electron groups = __________ __________ geometry.
Trigonal planar
The molecular geometry of four atoms with 120 degree bond angles in a plane.
Trigonal planar geometry
Different types of electron groups exert slightly different __________. Resulting bond angles reflect these differences.
Repulsions
In determine electron geometry, we consider only the electron groups on the __________ atom, rather than electron groups on the __________ atoms.
Central, terminal
The VSEPR geometries of molecules with two if three electrons around the central atom are _____-dimensional.
Two
Balloon models do not represent atoms; they represent __________ __________.
Electron groups
A geometrical shape with four identical faces, each an equilateral triangle.
Tetrahedron
The molecular geometry of five atoms with 109.5 bond angles.
Tetrahedral geometry
__________ is an example of a molecule with four electron groups around the central atom.
Methane
Five electron groups = __________ __________ geometry.
Trigonal bipyramidal
The molecular geometry of six atoms with 120 degree bond angles between the three equatorial electron groups and 90 degree bind angles between the two axial electron groups and the trigonal plane.
Trigonal bipyramidal
The angles in the trigonal bipyramidal structure are NOT:
All the same
The three bonds in the trigonal plane.
Equatorial positions
The angles between the equatorial positions are:
120 degrees
The two bonds on either side of the trigonal plane.
Axial positions
The angle between the axial positions and the trigonal plane is:
90 degrees
The molecular geometry of seven atoms with 90 degree bond angles.
Octahedral geometry (octahedral arrangement)
The octahedral geometry, there are _____ equatorial groups and _____ axial groups.
4, 2
The geometrical arrangement of electron groups.
Electron geometry
The geometrical arrangement of atoms.
Molecular geometry
When dealing with lone pairs, notice that the electron geometry and the molecular geometry are different; the electron geometry is __________ to the molecular geometry.
Relevant
Lone pair electrons generally exert slightly __________ repulsions than bonding electrons.
Greater
A lone electron pair is more spread out in space than a bonding electron pair because a lone pair is attracted to _____ nucleus while a bonding pair is attracted to _____.
1, 2
The lone pair occupies more of the __________ __________ around a nucleus.
Angular space
The lone pair occupies more of the angular space around a nucleus, exerting a __________ repulsive force on neighboring electrons.
Greater
A non-bonding electron pair occupies _____ space than a bonding pair.
More
As shown in a water molecule, it’s electron geometry is tetrahedral but its molecular geometry is __________.
Bent
The bond angle in H2O is even small than in NH3 because H2O has 2 __________ __________ on the central oxygen atom.
Lone pairs
The more lone pairs, the __________ the bond angles.
Smaller
The electron group (lone pair-lone pair) is:
Most repulsive
The electron group (bonding pair-bonding pair) is:
Least repulsive
The seesaw molecular geometry is sometimes called an:
Irregular tetrahedron
When a lone pair could occupy either an equatorial position or an axial position, the lone pair should occupy the position that __________ its interaction with the bonding pairs.
Minimizes
When a lone pair could occupy either an equatorial position or an axial position, the lone pair should occupy the position that minimizes its interaction with the bonding pairs. Therefore, it would occupy an:
Equatorial position
In seesaw molecular geometry, the lone pair never occupies the __________ position.
Axial
When two of the five electron groups around the central atom are lone pairs, the lone pairs occupy how many if the equatorial positions?
Two of the three
When 3/5 of the electron groups around the central atom are lone pairs, the lone pair occupies all three of the equatorial positions and the resulting molecular geometry is __________.
Linear
The molecular geometry of a molecular with octahedral electron geometry and one lone pair.
Square pyramidal
In molecular geometry diagrams, what is not shown?
Lone pairs
The molecular geometry of a molecule with octahedral electron geometry and two lone pairs.
Square planar
When 2/6 electron groups around the central atom are lone pairs, the lone pairs occupy positions:
Across from each other
When 2/6 electron groups around the central atom are lone pairs, the lone pairs occupy positions across for each other to minimize:
Lone pair-lone pair repulsions
The geometry of a molecule is determined by:
The # of electron groups on the central atom
The number of electron groups can be determined from:
The Lewis structure of the molecule
Each of the following counts as a single electron group:
A lone pair, a single bond, a double one, and triple bond, or a single electron
Double and triple bonds occupy _____ space than single bonds.
More
Which statement is always true according to VSEPR theory?
The shape of a molecule is determined by repulsions among all electrons groups on the central atom (or interior groups, if there is more than one).
What is the 1st step in predicting molecular geometries?
Draw a Lewis structure for the molecule
What is the 2nd step in predicting molecular geometries?
Determine the # of electron groups around the central atom
What is the 3rd step in predicting molecular geometries?
Determine the # of bonding pairs and lone pairs
What is the 4th step in predicting molecular geometries?
Use table 10.1 to determine the electron geometry and molecular geometry
Use this to represent a bond in plane of paper.
Straight line
Use this to represent a bond going into the paper.
Hatched wedge
Use this to represent a bond coming out of the paper.
Solid wedge
Larger molecules may have two or more __________ atoms.
Interior
