Test on Thursday November 3, 2016 Flashcards
What are the three Allotropes of Carbon?
Diamond
Graphite
Buckminsterfullerene
What is the Bond Angle of Tetrahedral?
109.5° (AB₄)
As the bonds go from single to double to triple, the length between atoms BLANK.
Decreases
Example:
C−C is 0.154nm
C=C is 0.134nm
C≡C is 0.120nm
What is the third order to consider for IMF strength? 3
Length of Carbon Chain
💨 Longer chain has higher IMF
💨 Branches on chains reduce IMF
What is the Bond Angle of Pyramidal? 2
109.5° > x > 90° (AB₃E)
Specifically 107°
What is the Bond Angle of (AB₂)?
180°
What is the Shape of (AB₂)?
Linear
What is the Bond Angle of (AB₄)?
109.5°
What is the Bond Angle of Trigonal Planar?
120°
360/3
What is the first order to consider for IMF strength? 3
Polarity of molecules
💫 More polar has higher IMF
💫 If both Non-Polar use #2
What is the Bond Angle of (AB₃E)? 2
109.5° > x > 90°
Specifically 107°
What type of molecules have Non-Polar and Polar ends and may dissolve in both (like soap).
Some chained molecules
What is the second order to consider for IMF strength? 3
Molar Mass of molecules
✨ Larger mass has higher IMF
✨ If both of equal mass use #3
What is the Bond Angle of (AB₂E)?
120° > x > 109.5°
What is the Bond Angle of (AB₂E₂)? 2
109.5° > x > 90°
Specifically 104.5°
Rank the following forces, (Ionic Bond, London Dispersion, Dipole-dipole, Covalent Bonds and Hydrogen Bonding) in order from weakest to strongest and provide an example of each.
London Dispersion
Dipole-Dipole
Hydrogen Bonding
Ionic Bonding
Covalent Bonding
What is the Bond Angle of Linear?
180°
What is ductility?
A metal’s ability to be drawn into a thin wire
What is the Shape of (AB₃)?
Trigonal Planar
What is an alloy?
A mixture of 2 or more metal atoms
What is the second order to consider for IMF strength? 3
Molar Mass of molecules
✨ Larger mass has higher IMF
✨ If both of equal mass use #3
Which liquids would Non-Polar covalent substances dissolve in?
They would dissolve in other Non-Polar liquids.
What is Malleability? 2
A metal can be bent and reshaped under pressure
Layers of positive ions can slide over each other reforming metallic bonds
What is the Bond Angle of Angular?
120° > x > 109.5° (AB₂E)
or
109.5° > x > 90° (AB₂E₂)
What is the Bond Angle of (AB₃)?
120°
What is the first order to consider for IMF strength? 3
Polarity of molecules
💫 More polar has higher IMF
💫 If both Non-Polar use #2
Explain the process of Hydration. 3
It occurs when Ionic Substances dissolve in water
Water molecules surround the ions at the edge of the lattice and pull them off.
The stronger the ionic bond, the less soluble the compound is in the water.
What is the Shape of (AB₃E)?
Pyramidal
What is the Shape of (AB₄)?
Tetrahedral
What are Intermolecular Forces? 4
Force of attraction between molecules
Also called Van der Waals’ forces
Much weaker than forces within molecules
The more Polar the molecule, the stronger its attraction to a neighboring molecule
Rank the following forces, (Ionic Bond, London Dispersion, Dipole-dipole, Covalent Bonds and Hydrogen Bonding) in order from weakest to strongest and provide an example of each.
London Dispersion
Dipole-Dipole
Hydrogen Bonding
Ionic Bonding
Covalent Bonding
What is the third order to consider for IMF strength? 3
Length of Carbon Chain
💨 Longer chain has higher IMF
💨 Branches on chains reduce IMF
What is the Shape of (AB₂E₂)?
Angular
What is the Shape of (AB₂E)?
Angular
What is the summation of Texture in Covalent solids? 2
They tend to be soft and waxy
Molecules slide past each other
What is a Metallic bond?
Metals form a lattice of positive ions in which valence electrons are free to roam, called delocalized electrons.
A Metallic bond is the electrostatic attraction between a lattice of positive ions and the delocalized electrons
What is the summation of /conductivity in Covalent substances?
They do not conduct electricity since they have NO FREE IONS or Electrons
The stronger the IMF, the BLANK energy is needed to separate the molecules.
More
What is the summation of Volatility in Covalent molecules? 2
They tend to be more volatile than ionic or metallic substances
Molecule breaks away more easily due to weak intermolecular forces
What is the fixed charge of Ag?
Ag+1
What is the general trend in Solubility between different kinds of compounds?
Like dissolves in Like
Is water Polar or Non-Polar?
Polar because there are two positive Hydrogens attracted to an Oxygen
What is the summation of Texture in Ionic substances? 2
They tend to be hard and brittle
Edges of lattice structure can break off
At what temperature will sodium chloride melt?
801°C
What are the 3 effects of Hydrogen Bonding?
HF, NH3 and H20 have unusually hugh boiling point and melting points compared with higher molar mass hydrides within their groups like HCl, PH3, and H2S, are all gases at room temperature
Water expands as it freezes. The molecules rearrange when they get close resulting in an open structure. Water is densest at 4°C and ice floats
DNA has a double helix structure.
The Hydrogen from one strand attracts to the nitrogen and oxygen in the other strand holding the strands together!
What is the fixed charge of Al?
Al+3
What is the summation of Texture in Covalent solids? 2
They tend to be soft and waxy
Molecules slide past each other
What is the summation of Melting and Boiling points in Covalent substances? 3
They tend to boil at lower temperatures than Ionic or metallic substances.
Non-Polar molecules break away more easily due to weak IMF
Takes less energy or lower temperature
What is Conductivity of electricity?
Flow of electrons
Delocalized electrons can move from one end of the metal quickly to the other
What is Hydrogen Bonding? 6
Special case of dipole-dipole forces
Creates a very strong intermolecular force
Common susbstances where hydrogen bonding occurs
Water (H20), ammonia (NH3) and HF Alcohols (R-OH), organic acids (R-COOH) DNA (Contains C, N, O and H)
What is the fixed charge of Zn?
Zn+2
At what temperature will water melt?
0°C
How can we make an Ionic solid conduct electricity?
We need to dissolve it in water
and
Melt it
==============
When the ions are free to move, electricity will be conducted
What are London Dispersion Forces? 4
Weakest IMF due to instantaneous induced dipoles
Will become stronger as
Molar mass of the molecule increases
Length of chained molecule increases
Will still occur between polar molecules but effect is minimal.
What is the summation of Texture in Ionic substances? 2
They tend to be hard and brittle
Edges of lattice structure can break off
What is the summation of Melting and Boiling points in Ionic substances?
Ionic compounds melt at very high temperature.
What is required in Hydrogen Bonding? 2
A very Polar Covalent bond of Hydrogen and another Small, more electronegative element (fluorine, oxygen, or nitrogen)
Attraction of above positive dipole hydrogen with a non-bonded electron pair of fluorine, oxygen or nitrogen atom in a neighbouring molecule
What is the fixed charge of Cd?
Cd+2
What are the 3 effects of Hydrogen Bonding?
HF, NH3 and H20 have unusually hugh boiling point and melting points compared with higher molar mass hydrides within their groups like HCl, PH3, and H2S, are all gases at room temperature
Water expands as it freezes. The molecules rearrange when they get close resulting in an open structure. Water is densest at 4°C and ice floats
DNA has a double helix structure.
The Hydrogen from one strand attracts to the nitrogen and oxygen in the other strand holding the strands together!
What is the summation of Volatility in Ionic susbstances? 2
They tend to be less volatile than Covalent or metallic substances
Ions are too strongly attracted to separate
What are the 2 types of dipole?
Permanent
and
Temporary/Induced Dipole
What are Coordinate Bonds?
Normally each atom shares one e- to form the Covalent Bond, bit in some cases, one atom share 2 e- with another for a single bond
What is the VSEPR Theory?
Model predicts the shape of molecules based on repulsion of e- pairs (e- domains)
E- arrange so that they are as far as possible from each other Unbonded pairs of e- will repel more than unbonded pairs
The BLANK the electronegativity difference, the more Polar the bond.
Higher
How to know if a molecule is Polar? 2
If the difference in electronegativity for the atoms in a bond is greater than 0.4, we consider the bond polar.
If the difference in electronegativity is less than 0.4, the bond is essentially nonpolar.
What is the strongest dipole-dipole force?
Hydrogen Bonding
What are Resonance Structures?
Is when you can sometimes draw more than one Lewis Diagram used to describe e- positions.
What are the 2 criteria for a molecule to meet in order to be Polar?
It must contain Polar bonds
The arrangement of the bonds must be asymmetic. Central atom has either:
Lone pair of e- and/or
Different atoms bonded to it
What is the E in VSEPR Theory?
The # of lone pairs
What does VSEPR Theory stand for?
Valence
Shell
Electron
Pair
Repulsion
What is the B in VSEPR Theory?
The # of bonded pairs around the central atom
What is the A in VSEPR Theory?
The central atom
How to know if a molecule is Non-Polar? 2
If the difference in electronegativity for the atoms in a bond is greater than 0.4, we consider the bond polar.
If the difference in electronegativity is less than 0.4, the bond is essentially nonpolar.
What is a Buckminsterfullerene? 3-5
Consists of 60 carbons arranged in hexagons and pentagons
Similar to a soccer ball pattern
Other similar carbon molecules isolated
Led to a new branch of science
Nanotechnology
What is a diamond? 5-6
A giant Covalent structure.
Single molecule is very large
3D structure where each carbon atom is covalently bonded to four other carbon atoms.
All bonds are equal, no plane of weakness
Very hard, very high melting point
Formed under pressure, but aren’t forever
Why is Buckminsterfullerene a molecule? 2
Because they can make bonds like water.
There is a limit to how big a Diamond and Graphite can be.
What are other giant Covalent structures other than Diamond? 2
Sand
Pure Silicon
What is a graphite? 5-7
Organized into layers of hexagonal rings
Each carbon atom is strongly bonded to three other carbons within the layer
Very weakly bonded to carbons in layers above and below
Layers can slide across each other
Good lubricant and write well
Electrons delocalized between layers
Good conductor of electricity
