Chemical Bonding

Question 1

covalent compounds

Answer 1

partial sharing leads to a covalent bond

Question 1

ionic compounds

Answer 1

transfer of electrons from one element to another (metal to nonmetal)

Question 2

metallic bonding

Answer 2

electrons are pooled: atoms are kept together through the interaction of the positively charged nuclei with a cloud of electrons that is shared between all atoms

Question 3

atoms that differ in electronegativity

Answer 3

the electrons are attracted by the atom with higher electronegativity

Question 4

resonance forms

Answer 4

the electrons are delocalized in a hybrid structure: identical bond lengths

Question 5

how do we distinguish between plausible bonding schemes?

Answer 5

by choosing the structure with the smallest formal charge and the negative charge on the more electronegative atom

Question 6

formal charge

Answer 6

number of valence electrons - number of lone pairs - number of bonding electrons/2

Question 7

radicals

Answer 7

species with an odd number of electrons and are usually unstable and very reactive

Question 8

which elements can form more than 4 bonds

Answer 8

if an atom belongs to the 3rd period or more

Question 9

when will a bond form

Answer 9

if there is an energetic gain in the process

Question 10

bond energy

Answer 10

the energy required to break one mole of identical bonds

Question 11

vsepr

Answer 11

electrons in bonds and lone pairs will arrange in space to minimise charge- charge repulsions

Question 12

linear geometry

Answer 12

180 degrees
2bp

Question 13

trigonal planar geometry

Answer 13

120 degrees
3bp

Question 14

tetrahedral geometry

Answer 14

109.5 degrees
4bp

Question 15

bent

Answer 15

2bp + 2lp

Question 16

trigonal pyramidal

Answer 16

3bp + 1lp

Question 17

how can a bond be polarised

Answer 17

due to the electronegativity difference between the atoms.

Question 18

hybridization

Answer 18

the combination of different atomic orbitals with similar energies to form isoenergetic orbitals identical in shape

Question 19

why is h2O a bent molecule

Answer 19

due to hybridization

Question 20

sigma bond

Answer 20

formed by the head-on overlap of atomic orbitals

Question 21

strength pi and sigma bond

Answer 21

pi bonds are weaker than sigma bonds

Question 22

discuss the rotation around a single or a double/triple bond

Answer 22

rotation about a single bond is free, around double or triple bonds is not

Question 23

draw the molecular orbital diagram for when Zavg is less than 8

Answer 23

see notes

Question 24

draw the molecular orbital diagram for when Zavg is greater or equal to 8

Answer 24

see notes

Question 25

bond order

Answer 25

bond order = (electrons in bonding orbitals - electrons in antibonding orbitals)/ 2

Question 26

bonding molecular orbital

Answer 26

the sum of the wave function: a region where it is more likely to find an electron

Question 27

antibonding molecular orbital

Answer 27

subtraction of the wave function: does not favor the formation of a molecule

Question 28

paramagnetism

Answer 28

unpaired electrons: attracted to the magnetic field

Question 29

diamagnetism

Answer 29

paired electrons: repelled by a magnetic field