Chapter 5 Flashcards
how to determine the formal charge on an atom
atomic number - #valence electrons -nnumber of bonds
what does the size of the dipole do
if the larger the dipole, the stronger the harder it is to pull molecules away from eachother. consequenty. the higher the boiling point is
resonance structured
different lewis structures for the same compound
formal charge
the charge an atom would have in a molecule if all bonds were shared equally
the sum of the formal charges is equal to
the charge of the molecule
where should the negative formal charges go if they must occur
on the most electronegative element
vesper
electrons in one pair or bond repel eachother.
electronic geometry
the geometry for all of the electron groups the basic one
molecular geometry
the geometry just accounting for the elements this is the complex one
4 electron groups eg
tetrahedral 109.5
3 electron groupseg
trigonal planar 120
2 electron groups eg
linear 180
4 electron groups 1 lp mg
trigonal pyramidal <109.5
4 electron groups 2 lp mg
bent <109.5
how does bond length affect bond angle
as bond length increases the bond angle decreases as elements become easier to move together
how does atomic radius affect thebond angle
the larger the atomic radius, the smaller the angle is
as a carbon carbon increases in number of bonds what happens
the bond dissociation energy increases and the length decreases
Do resonance structures always contribute equally to the overall structure of a molecule? why
no
Just because a molecule can have multiple resonance structures, that does not mean that it is the most desired for the molecule. Molecules tend to prefer smaller or 0 values for the formal charges. On top of that it is best to put the negative formal charge on the most electronegative element.
What constitutes an electron group?
Electron groups are defined by as lone pairs, single bonds,multiple bonds, and even single electrons define them. They repel each other through coulombic forces.
How do you determine whether a molecule is polar?
- Determine whether the polar bonds add together to form a net dipole moment.
- Draw the Lewis structure for the molecule and determine the molecular geometry.
- Determine whether the molecule contains polar bonds.
Which of the two compounds, H2NNH2 and HNNH, has the strongest nitrogen-nitrogen bond, and which has the shorter nitrogen-nitrogen bond.
HNNH has both the strongest nitrogen-nitrogen bond and the shorter nitrogen-nitrogen bond.
the double bond is stronger and shorter
what causes bond andgles to deviate
their bond angles should deviate from the idealized bond angle as lone pairs are more repulsive than bonding pairs of electrons. Large atoms, such as Cl or Br, will cause bond angles to deviate from the ideal, and the presence of a multiple bond will cause a deviation as well owing to the increased electron density, so COCl2 should deviate from the idealized bond angle. CH4 has identical atoms symmetrically surrounding a central atom with no lone pairs on it, so CH4 should not deviate from the idealized bond angle.`
Which explanation best predicts which species has the smaller bond angle, ClO4− or ClO3−
ClO3− will have the smaller bonding angle since it contains one lone pair of electrons, and lone pair–bonding pair repulsions are greater than bonding pair– bonding pair repulsions.
studdy fin mas to formula do it it will be there i sense it
