1Properties of giant ionic lattices (ionic compounds)
- They have very high melting and boiling points
- Soluble in polar solvents
- Dont conduct electricity when solid but can when molten or dissolved.
2Whats a dative covalent bond
When one atom shares lone pair of electrons to form a bond
3What is electron pair repulsion theory
- Each pair of electrons in an atom will repel all other electrons pairs
- Pairs of electrons therefore will move as far apart as possible to minimise repulsion
4What is VESPR theory
the shape a molecule takes is based on the electron pairs repulsion
5What to do if they have charges first step when prediciting shape
- If it has a positive charge, remove electron from least electronegative element and the opposite for if negative charge.
6what is electronegativity
An atoms ability to pull a pair of electrons in a covalent bond
7electronegativity trend
Same as ionisation
8How to determine a molecule is non polar?
If the difference in electronegativity is less than 0.5
9How to tell if a molecule is ionic with electronegativity
If the difference in electronegativity is equal to or greater than 2.5
10How tell if a molecule is covalent
If the difference in electronegativity is less than 2.5
11How to tell if an element is a metal
If its electronegativity is equal to or less than 1.5
12How to tell if an element is covalent
If its electronegativity is equal to or greater than 2.1
13Order from strongest on top strength of INFS
Hydrogen
Dipole dipole
Van der waal
14What are dipole dipole forces
forces of attraction that occur between opposite charged atoms in polar different molecules
15Between what elements can hydrogen bonding only occur with
N O F
16What is hydrogen bonding
It happeneds when hydrogen is covalently bonded to a NOF with a lone pair of electrons
17What are van der waals forces
Its when electrons in one molecule ends up on one side creating a temporary dipole which induces a temporary dipole on another molecule causing electrostatic attraction.
18what is the LIKE dissolves LIKE
polar dissolves polar, nonpolar dissolves nonpolar
19How is ice less dense than liquid water?
This is because the hydrogen bonds in ice holds the molecules further away resulting in large gaps. Called an open lattice structure which takes up more volume than liquid water would.
20how does hydrogen bonding actually work?
The partially positively charged hydrogen is attracted to the lone pair in negatively charged NOF in another molecule, forming an electrostatic attraction