Shape of small molecules
shape of small molecules
polarity
polarity
miscellaneous
100
What does VSEPR stand for?
Valence Shell Electron Pair Repulsion. It states that the pairs of valence electrons are arranges as far apart from each other as possible. it can be used to predict the shape of a wide variety of molecules
100
How do hybrid orbitals form?
When an atom forms a bond, its atomic orbitals combine to form hybrid orbitals which have a combination of the shapes and properties of atomic orbitals. sp = linear sp2 = trigonal planar sp3 = the rest
100
What are the 2 factors that determine the polarity of a molecules?
shape and polarity of its bonds
100
polar molecules tend to ______ a. attract one another b. repel one another
attract one another
100
how does polarity help to give proteins their 3D shape?
proteins contain polar side chains and non polar side chains. for several reasons, including polarity, a protein bends and twists itself into a complex 3D shape
200
What are ball and stick models? Why are they useful?
The ball represents an atom's nucleus, an inner level electrons. the balls are connected either with straight sticks (single bonds) or curved springs (multiple bonds) Used to represent bond angles and 3D molecular shapes
200
the bond angle associated with sp2 orbitals is...
120 degree (trigonal planar)
200
what is dipole?
a polar molecule or dipole has one end with a positive charge and one end with a negative charge
200
in a trigonal planar molecule, the orbitals around the central atom are ____ orbitals
sp2
200
water is an example of a _____ (polar,non polar), ______ (linear, bent) molecule
polar, bent
300
Give 5 common shapes of small molecules. provide examples for each.
Linear - carbon dioxide Trigonal Planar - BCl3 Tetrahedral - methane pyramidal - NH3 bent - water
300
1. what type of molecule does not have sp3 orbitals. a. pyramidal b. bent c. linear 2. the hybrid orbitals in carbon dioxide are… a. sp b. sp2 c. sp3
1.linear 2. sp
300
1. why is water a polar molecule? 2. why does water have different properties than carbon dioxide?
1. the bent shape contributes to its polarity 2. because water is polar and carbon dioxide is non polar
300
in a small molecule, the electrons' atomic orbitals combine to form ____ orbitals
hybrid
300
what factors determine the polarity of a molecule?
shape and electronegativity
400
2 important trends in bond length
the larger the atoms, the longer the bond between them the more electron pairs share in a bond, the shorter the bond
400
1.Boron trichloride is an example of _____ molecule 2. the bond angles in a linear molecule are ______
1.trigonal planar 2. 180 degrees
400
A dipole is a polar molecule. true or false?
true
400
a single bond b/w two atoms is probably _____ than a double bond b/w the same two atoms
longer
500
what is a bond angle. give example.
Geometric angles b/w two adjacent bonds - linear - carbon dioxide = 180 degrees trigonal planar - BCl3 = 120 degrees tetrahedral - methane - 109.5 degrees pyramidal - ammonia - 107 degree bent - water = 105 degree
500
1.the geometric angle between two adjacent bonds is called ______ 2. the shape of methane is ______ a. square b. pyramidal c. tetrahedral 3. how does water's shape determine its properties?
1. bond angle 2. tetrahedral 3. water is a bent, polar molecule. positive and negative ends to adjacent molecules are attracted to each other; resulting in an unusually high boiling and melting point
500
how can drawing arrows help you decide whether a molecule is polar or non polar
by examining all the arrows present in a molecule, you can determine whether or not the arrows cancel each other. if they do, the molecule is non polar
500
compared with shared pairs of valence electrons, unshared pairs exert _____ a. greater repulsion force b. a lesser repulsion force
a. greater repulsion force
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