KEMINO Review 1

Covalent bonding

• giving and taking of electrons

• sharing of electrons

• between metal and non metal

• between 2 non metals

Answer explanation

or transition metal and coordinate covalent bond with ligands

usually to complete octet rule or duet rule

Bond strength from weakest to strongest

• single < double < triple

• triple < double < single

• single < triple < double

• double < triple < single

Answer explanation

inverse for bond length

differences are due to electron density around the bond (electrostatic attraction between electrons and positive nuclei of the bonding atoms)

which has a broader electron cloud and why

• bonding electron clouds because repulsion with positively charged atoms

• non bonding electrons because more repulsion between electrons than bonding

• bonding electrons because bond allows electrons to deviate past the internuclear plane more

• non bonding electrons because 2 positively charged atom nuclei are repelling against each other

Answer explanation

since NB only has 1 positively charged nuclei there is more repulsion than B

B has 2 positively charged nuclei on each end leading to more attraction than repulsion resulting in denser electron cloud

a bond where the electronegativity difference of 1.8 would be

• non polar covalent

• polar covalent

• ionic

• metallic

Answer explanation

0 = non polar covalent

0 to 2 = polar covalent

more than 2 = ionic

electronegativity is

• Competing for electron in a bond

• ability for an atom to attract electron to itself

Answer explanation

the other is electron affinity, aka energy released when electron is added onto an atom

What can lewis structures show

• type of bond

• energy of a bond

• distribution of v.e.

• enthalpy change

Answer explanation

shows which are lp and which are bonded

HOW TO LEWIS

base v.e. of atoms + charge (if negative add if positive subtract)

v.e. with octet/duet fulfilled

difference = number of bonds

draw skeletal structure adjust with bonds (subtract with number in 1)

fill with lp from terminal to central (subtract from 1)

which formal charge is most to least stable for central atom

• +1, 0, -1

• -3, -2, -1

• 3, 2, 1

• 1, -2, 3

Answer explanation

closer to 0 = more stable

sum of formal charges in a compound will be equal to

• number of atoms in the compound

• charge of the central atom

• charge of the terminal atoms

• charge of the compound

Answer explanation

How to get FC:

v.e. in base electron - (lp + 1/2 bp) aka sum of lines and dots

what are resonant structures

• structures that are mirror images of each other

• structures that carry resonant frequency when sound passes

• structures that only occur in expanded octets

• structures that collectively describe the bonding in an atom

Answer explanation

when there is more than one position for a multiple bond in a compound represent fractional bonds in an atom e.g. (approx 1.5 bond in CO3)

What is NOT an exception to the octet rule

• incomplete

• expanded

• odd number of electrons

• duet

• even number of electrons