Chapter 6 - Shapes of molecules and intermolecular forces Flashcards
(28 cards)
What shape would a molecule with one lone pair and three bonded pairs be?
Pyramidal
What shape would a molecule with two lone pair and two bonded pairs be?
Non-linear
What shape would a molecule with 2 electron regions be?
Linear
What shape would a molecule with 3 electron regions be?
Trigonal planar
What shape would a molecule with 4 electron regions be?
Tetrahedral
What shape would a molecule with 6 electron regions be?
Octahedral
How much closer to lone pairs push bonds together?
2.5 degrees
What is electronegativity?
The ability of an atom to attract the bonding electrons in the covalent bond.
What is used to measure electronegativity?
The Pauling scale.
What is the bond type if the electronegativity difference is 0?
Covalent.
What is the bond type if the electronegativity difference is 0 to 1.8?
Polar covalent.
What is the bond type if the electronegativity difference is greater than 1.8?
Ionic.
What are two points about non-polar bonds?
The bonded electron pair is shared equally between atoms and they have the same/similar electronegativity.
Describe a polar bond.
A bond where the bonded electron pair is shared unequally between the bonded atoms.
What are the three types of intermolecular force?
- Induced dipole-dipole interactions(London forces)
- Permanent dipole-dipole interactions
- Hydrogen bonding
Summarise induced dipole-dipole interactions (London forces).
The movement of electrons produces a changing dipole in a molecule which induces dipoles on neighbouring molecules.
Are non-polar simple molecular substances soluble in non-polar solvents?
Yes.
Are non-polar simple molecular substances soluble in polar solvents?
No.
Are polar simple molecular substances soluble in polar solvents?
Yes.
Why can’t simple molecular substances conduct electricity?
There are no mobile charged particles in the simple molecular structures so there’s nothing to complete an electrical circuit.
Hydrogen bonding occurs between hydrogen and what three other elements?
Nitrogen (N), oxygen (O) and Flourine (F).
Why does ice float?
It is a rigid structure which is less dense than water as the molecules are held further apart.
what bond angle is in tetrahedral molecules?
109.5
what bond angle is in pyramidal molecules?
107
