Structure and Bonding

Question 1

How can we rank different ionic compounds based on their melting points ?

Answer 1

Ionic bonds are formed through Coulomb’s Force between anion and cation - thus the smaller the radius the stronger the force thus higher melting point

Question 2

What determines if the bond between 2 atom is going to be ionic or covalent ?

Answer 2

Electronegativity difference - reference 1.9

Question 3

Which molecules will orient themselves in an electric field ?

Answer 3

Molecules that have a permanent dipole moment

Question 4

What shows charge distribution in a molecule ?

Answer 4

Electrostatic potential maps

Question 5

Difference between polar and nonpolar in terms of EN ?

Answer 5

EN less than 0.5 will not form charge difference thus no permanent dipole moment = nonpolar molecule

Question 6

How does Resonance structures differ ?

Answer 6

They only differ by the electron distribution, the connectivity is the same

Question 7

Which resonance structure exist in real life ?

Answer 7

None of them. Its the average of the structures

Question 8

Bond order

Answer 8

butun resonance structure topluyorsun specific hangi bond ise sonra resonance structure sayisina boluyorsun

Question 9

How to assign formal charges ?

Answer 9

Valance electron sayisi - etrafindaki electron sayisi

Question 10

VSEPR Theory

Answer 10

predicts bond angle - shape

Question 11

Is a tetrahedral structure polar or nonpolar ?
A2B2

Answer 11

The ones in the same plane can cancel out but you can not cancel the other 2 because they can never be in the same plane - thus nonpolar

Question 12

Why water is polar ?

Answer 12

Because EN difference is not 0 thus it has a dipole moment

Question 13

What does it mean “ intermolecular forces” ?

Answer 13

between molecules - affects physical properties

Question 14

What affects the degree of dispersion forces (London forces) ?

Answer 14

Surface area of the molecule
in other words larger electron density = larger dispersion forces
also momentary not continuous

Question 15

Hydrogen interaction between what and what

Answer 15

The lone pair on the oxygen and hydrogen on another molecule
attention!! - intermolecular forces

Question 16

How many hydrogen bonding in a water molecule ?

Answer 16

4

Question 17

Why C-H bonds cannot participate in hydrogen bonding ?

Answer 17

Because C-H bonds are not polar enough - EN difference

Question 18

What happens to the number of hydrogen bonds in a water molecule as it changes phases from gas to liquid ?

Answer 18

Becoming stronger thus more hydrogen bonds

Question 19

what does VBT answer ?

Answer 19

Focuses on atoms instead of molecules - also to explain bond angles

Question 20

sigma bond

Answer 20

the overlap of 2 orbitals are on the axis

Question 21

what happens after the overlap of 2 orbitals ?

Answer 21

the electrons are LOCALIZED between the 2 nuclei - restricted to an area

Question 22

hybridization ?

Answer 22

mixing of orbitals in the same atom

Question 23

what does hybridization explain in VBT?

Answer 23

it explains bond angles in the orbital level - localized approach

Question 24

what does the number of electron density decide ?

Answer 24

for example - tetrahedral electronic arrangement !!!
SHAPE DOES NOT MATTER IN VBT

Question 25

if electron density = 4

Answer 25

tetrahedral electron arrangement
109.5

Question 26

sp3d hybridization

Answer 26

5 regions of electron density - trigonal bipyramidal electron arrangement - 90, 120, 180

Question 27

pi bond overlaps where ?

Answer 27

sideways - they are 90 degree to the plane

Question 28

how to count pi bonds ?

Answer 28

4 lobes - 2 overlap with each other on 2 sides but only forms 1 pi bond

Question 29

molecular orbital theory

Answer 29

describes bonding in terms of molecular orbitals that are formed by combining atomic orbitals
-also explains paramagnetism, diamagnetism

Question 30

paramagnetic molecules

Answer 30

at least 1 unpaired electron

Question 31

diamagnetic molecules

Answer 31

no unpaired electrons

Question 32

which one creates a node ?
bonding orbital or antibonding orbital

Answer 32

antibonding orbitals create a new node between the 2 nuclei oyuzden adi antibonding

Question 33

which one higher energy bonding or antibonding orbital ?

Answer 33

antibonding because its trying to deconstruct the bond

Question 34

Filling the elecrons from what to what MOT ?

Answer 34

from lowest energy to higher from bonding to antibonding

Question 35

Why there is no 2px pi bond ?

Answer 35

Because its a bond on the axis thus thats the definition of a sigma bond

Question 36

Bond order in MOT

Answer 36

bonding electrons - nonbonding electrons /2