Bond Types and Nomenclature
Intermolecular Forces
Molecular Geometry and Lewis Structures
Carbon Allotropes and Extra Q's
Metallic Bonds, Conductivity, Solubility
100
What kind of internal bonds does the compound NH4+ have? (Type and polarity)
polar covalent
100
What are the three elements that can make hydrogen bonds?
F, O, N
100
Draw the Lewis dot structure for water
H-:O:-H (two lone pairs on O)
100
Name the three carbon allotropes.
Diamond, graphite, fullerene/buckyballs/C60
100
What does it mean for something to be conductive?
Charges can flow freely
200
What kind of compound is MgSO4? What is its name?
ionic, magnesium sulfate
200
What's the molecular difference between a liquid and a gas?
Intermolecular forces are all broken when gaseous
200
What is the shape and bond angle of CH4?
Tetrahedral, 109.5
200
Name two differences between diamond and graphite.
Diamond is hard, graphite is soft -- graphite is in layers Diamond is not conductive, graphite is-- delocalized e- vs all e- in covalent bonds
200
Why are metals malleable and ductile? What do those words mean?
The delocalized e- can slide over each other, allowing for bonds to shift without a net loss or gain of bonds between e- and positive ions
300
What is the chemical formula (and charge) for bicarbonate?
HCO3-
300
Which substance would have the lowest melting point? Why? CH4 CH3Cl CH2OH
Lowest is CH4 because dispersion forces are the weakest (vs dipole-dipole or h-bonds)
300
What is the shape and bond angle for PH3 and why?
trigonal pryamidal, 107, smaller than 109.5 because lone pair repels more
300
What is a "macromolecule" or a "network covalent solid"? Give an example that is not carbon-based.
A covalent molecule that extends in all directions. Silicon (looks like diamond with tetrahedral bonds between Si) and SiO2 (silica, quartz, silicon dioxide; also tetrahedral but with a ratio of 1:2 of Si:O)
300
What does "like dissolves like" mean?
Polar dissolves polar; non-polar dissolves non-polar. Solute and solvent must match.
400
How do you know if a bond is non-polar, polar, or ionic?
non-polar: little to no difference in electronegativity (<0.4, which is C-H bond) polar: less than 1.8 difference (greater than 0.4) ionic: more than 1.8 difference
400
Which substance would have the highest boiling point, and why? CH4 C2H6 C3H8 C4H10
C4H10 because more mass means more electrons, which means more dispersion/van der Waals forces. Need more energy to break all of those forces to make into a gas.
400
Which of the following are polar molecules? Name all the substances, also! NH3 NH4+ H2O H3O+
NH3 - polar, ammonia NH4+ - non-polar, ammonium ion H2O - polar, water H3O+ - polar, hydronium ion
400
Explain the three intermolecular forces, and the difference between them.
Disperson/van der Waals forces: weakest force based on spontaneous e- alignment, temporary dipoles Dipole-dipole forces: permanent dipole attraction between polar molecules Hydrogen bonding: very strong polar bonds between N, F, or O and H (eg H2O) that have bonds between the hydrogen on one molecule and the N, F, or O on the next molecule
400
How does soap work? Why?
Polar head bonds with polar water, non-polar tail bonds with non-polar dirt/grease. Like dissolves like!
500
Which molecule is most similar in shape to NH3? GaI3 BF3 FeCl3 PBr3
PBr3 because lone pair makes it trigonal pyramidal. (107) BF3 is trigonal planar. (120) Gallium and iron make ionic bonds, so they don't have a molecule shape! They make ionic lattices.
500
Which molecule has the smallest bond angle? CO2 CH4 NH3 C2H4 H2S
H2S because bent with two lone pairs (104.5)
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