Chemical Bonding Flashcards
(33 cards)
Where is ionic bonding found?
In non metals and metals
Electrons transferred from metal to non metals and metals
What structure do Ionic compounds form!?
Ionic lattice every ion is surrounded by oppositely charged ions and held by electrostatic forces of attraction
How does this affect melting point?
High melting point bvz required lots of energy to break electrostatic forces of attraction
Stronger charge of ion higher melting point
How does this affect solubility?
Bcz the particles in ionic lattice are polar there hydrophilic so water molecules can come between the ions and intermolecular forces and form bonds
The stronger the charge the less soluble because it’s harder for the water molecules to overcome the stronger electrostatic forces of attraction
How does this effect solubility?
Bcz the particles in ionic lattice are polar there hydrophilic so water molecules can come between the ions and intermolecular forces and form bonds
The stronger the charge the less soluble because it’s harder for the water molecules to overcome the stronger electrostatic forces of attraction
How does this affect electrical conductivity?
The ions in the lattice are charged particle when aqueous or molten they become mobile so they can carry a charge and conduct electricity
What is a covalent bind and where is it?
Shared pare of electrons between non metal and non metal
C-C
What is expansion of the octet?
More then 8 electrons can be hosted if the atom contains a 3D sub shell elements in period 1 and 2 cannot Bcz they have no 3D sub shell
What is a dative covalent bond and how is it formed?
A shared pair of electrons that both come from 1 atom
Formed only if one has a lone pair of electrons and shared it with an atom that is electron deficient
Has same properties as a normal covalent bond but represents as an arrow to the electron deficient atom
Give me all the shapes of molecules names and bond angles for those with no lone pairs?
2BP 0LP / linear 180 degrees
3BP 0LP / triginal planar 120 degrees
4BP 0LP / tetrahedaral 109.5
5BP 0LP / triginal bipyramidal 90 degrees and 120 degrees
6BP 0LP / octahedral 90 degrees
How are shapes of molecules formed and what are the ways of representing the bond direction?
Determined by electron repair repulsion theory the electrons repel as far away as possible
Solid wedge = in front of plane
Dotted wedge= behind plane
Straight line= on plane
What is the different of the shapes of ionic molecules?
No difference
What is the effect of lone pairs on shapes of molecules?
Lone pairs repel more strongly then bonding pairs they decrease other bond angles By 2.5 degrees and are treated as a bonding area aswell
Give me the additional shapes of molecules names including lone pairs?
2BP 2LP / non linear or v shaped
Bond angle 104 .5 degrees (water molecule)
3BP 1LP / pyramidal bond angle 107.5 degrees
What is electronegativity?
The ability for an atom to attract the pair of electrons in a covalent bond to its nucleus
What is the trend of electron negativity?
increases from left to right and
Also increases from bottom to top with flourine being the most electron negative
What factors affect electron negativity?
Same as ionisation energy
1 atomic radius
2 shielding
3 nuclear charge
How can a bond be polar and what is the name of the other way it can be?
When a covalent bond forms between 2 atoms with different electronegativities then the more electronegative one pulls the electrons closer gaining a slightly - charge and the other a slight positive (polar bond)
Atoms with same of similar elecronegativities are called pure bond and aren’t polar
What is the charge called and how else can it be presented?
Charge is called a dipole and can also be represented with an arrow pointing to more electronegative element because is has a charge in one direction this is called the dipole moment or overall polarity
Describe the rules of overall polarity In molecules?
Some molecules have multiple polar bonds if these are symmetrical in all directions the the dipoles are cancelled out giving no overall polarity
But if not then the molecule has an overall polarity in a direction
Why do simple molecular substances have low melting and boiling points?
Because they are small they are held tgthr only by IF when heated the simple molecular substances vibrate and agin kinetic energy breaking the IF
What are the 3 types of IF from weakest to strongest?
- Induced dipole interaction ( London forces/ dispersion forces/ van de valls forces)
- Permanent dipole dipole interaction
- Hydrogen bonds
Describe induced dipole dipole interaction?
Electrons are always randomly moving so at a slight sexond there will be more electrons on one side of the atom creating a slight negative charge on one side and slight positive on other ( instantaneous dipole)
This will trigger the electrons in the other atom to repel and so on like a domino effect ( induced dipole)
These slight charges will cause the atoms to be attracted to eachother (van de walls forces)
What effects van de walls forces and where are they found?
Atoms with more electrons will have stronger van de walls forces
And they are found in every atom
