Bonding (3.1.3-Phys.) Flashcards
(27 cards)
What makes ionic bonds strong?
Electrostatic attraction between oppositely charges ions
How are ionics formed?
Transfer of valence electrons
The strength of the bond increases as….
Charge increases and size decreases
How can ions conduct?
If they are liquid or aqueous since this is the only time where the ions can move
Between NaCl and KCl, which has the higher melting point and why?
NaCl because it’s the smaller ion and so it has a shorter and stronger attraction.
Between NaCl and MgCl2, which has the higher melting point and why?
MgCl2 because it has a higher ionic charge, a smaller ionic radius and more delocalised electrons
When do ionic bonds form?
Between atoms with large differences in electronegativity
How strong are simple molecular covalent bonds?
Very strong
How are simple molecular covalent bonds formed?
Through a shared pair of electrons
Short bond=
Strong bonds
Why do simple molecular covalent bonds have low mpt/bpts?
They have weak intermolecular forces that require very little energy to overcome
Why can’t simple covalents conduct?
Because they don’t contain any moving charged particles
What occurs in dative covalent bonding?
One atom donates both electrons to share with the other atom(s)
Name 3 forces between molecules with simple covalent bonds
- Van Der Waals forces
- Permanent dipole-dipole
- Hydrogen bonding
Which is the weakest intermolecular force?
Van der Waals
- Exists btwn all simple covalent bonds
- Non polar bonds
- Temporary dipole of 1 molecule induces a dipole in another molecule
- Spherical forms have lower SA and fewer vdw, lower bpt
Which is the second strongest intermolecular force?
Permanent dipole-dipole
- Slight charges due to difference in electronegativity
- polar molecules
- non-symmetrical
What is the strongest intermolecular force?
Hydrogen bonding
- Bonded to N, O and F only
- Short strong hydrogen bonds
Why does S8 have a low mpt?
Very little energy required to break weak van der Waals forces
Which has a higher mpt S8 or P4?
S8 because its bigger, so it will have more van der Waals forces between molecules.
Why is ice less dense than water?
As water cools, there is a higher % of H bonds and the lattice structure formed. H bonds spread out pushing mol. away.
What makes metallic bonds strong?
Forces of electrostatic attraction bwn delocalisd electrons and +ve metal ions.
Higher strength =
Higher charge and smaller size
Why can metals conduct electricity?
They can carry charge through delocalised electrons that can move.
High charge density =
Stronger ions
