Exam Q 26

Question 1

define electronegativity

Answer 1

Electronegativity is the relative attraction that an atom in a molecule has for the shared pair of electrons in a covalent bond

Question 2

account for the increase in electronegativity values across the second period of the periodic table

Answer 2

The effective nuclear charge is increasing and the atomic radius is decreasing along the 2nd period of the periodic table

Question 3

use electronegativity values to predict the type of bonding in oxygen difluoride (OF^2)

Answer 3

polar covalent as 3.98-3.44= .54

Question 4

what electronegativity difference indicates ionic bonding in a compound?

Answer 4

An electronegativity difference greater than 1.7 indicates ionic bonding in a compound

Question 5

what electronegativity difference indicates covalent bonding in a compound?

Answer 5

An electronegativity difference less than or equal to 1.7 indicates covalent bonding in a compound

Question 6

what electronegativity difference indicates that the covalent bonding in a compound is polar covalent?

Answer 6

A difference greater than 0.4 and less than 1.7 indicates that the covalent bond is polar covalent

Question 7

what electronegativity difference indicates that the covalent bonding in a compound is non-polar covalent?

Answer 7

A difference less than or equal to 0.4 indicates that the covalent bond is non-polar covalent

Question 8

State and account for the shape of the OF^2 molecule

Answer 8

v-shaped planar

account: 2 bond pairs and 2 lone pairs

Question 9

select, giving your reasons, which of these angles is the most probable value for the bond angle in oxygen difluoride
180, 109.5, 120, 103 degrees

Answer 9

103 degrees:
As there are two bond pairs and two lone pairs, the lp-lp repulsion is stronger than lone pair/bond pair repulsion and that is stronger than bond pair/bond pair repulsion. This reduces the size of the regular angles