Bonding & Structure Flashcards
(26 cards)
What kind of attraction exists in ionic bonding?
Electrostatic
What is the formula of the sulfate ion?
SO4 ^2-
What are properties of ionic compounds?
They dissolve in water, they conduct electricity when molten or dissolved and they have high melting points
What is the formula of the nitrate ion?
NO3 -
What is a dative covalent bond?
A bond in which both electrons in the bond come from one atom
What are repulsions?
Electrons in covalent bonds repel and try to stay as far away from each other as possible, this determines the geometry of the molecule
Why do lone pairs repel each other more than bonding pairs?
Because they are held physically closer to the nucleus of an atom
What will the shape name and the bond angle be of a molecule where the central atom has 3 electron pairs?
Trigonal planar
120•
What will the shape name and the bond angle be of a molecule where the central atom has 2 electron pairs?
Linear
180•
What will the shape name and the bond angle be of a molecule where the central atom has 4 electron pairs (one of which is a lone pair)?
Trigonal pyramidal
107•
What will the shape name and the bond angle be of a molecule where the central atom has 4 electron pairs?
Tetrahedral
109.5•
What shape is a water molecule?
What is the bond angle?
Non-linear
104.5•
What will the shape name and the bond angle be of a molecule where the central atom has 6 electron pairs ?
Octahedral
90•
Define the term electronegativity
Where are the most electronegative atoms on the periodic table?
The tendency of an atom to attract a pair of electrons
The top right
What does difference in electronegativity between two bonding atoms result in?
One atom in a bond will develop a partially + charge and the other will develop a partially - charge. This will create a polar bond, specifically a permanent dipole.
What is the Pauling scale value for fluorine?
4
What is the Pauling scale value for oxygen?
3.4
What is the Pauling scale value for chlorine?
3.2
What is the Pauling scale value for nitrogen?
3.0
How can a molecule be polar?
When will this not be possible?
If there is a charge separation between one side of the molecule and the other (due to bonds) there will be a permanent dipole.
If bonds are arranged symmetrically about the centre of the molecule.
What is a permanent dipole-induced dipole interaction?
Due to the polarity of the molecule with a permanent dipole it is able to cause electrons in the shells of a nearby molecule to shift. This shift will be due to attraction or repulsion and will cause the non-polar molecule to become slightly polar.
What are the 3 Van der Waals’ forces from strongest to weakest?
Permanent dipole-dipole
Permanent dipole- induced dipole
London forces
What are London forces?
Forces caused by the constant random movement of electrons within atoms’ shells. This creates an instantaneous dipole which induces a dipole in neighbouring molecules.
What is a permanent dipole- permanent dipole interaction?
The partially positive ends of molecules with permanent dipoles will attract the partially negative ends of other molecules with permanent dipoles
