Molecular Shape

Question 1

What does is VSEPR?

Answer 1

each molecule will assume a shape that minimizes repulsion

Question 2

What are considered electron groups? Are double bonds counted as two groups or one?

Answer 2

single/double/triple bond or lone pair

one

Question 3

What does it mean if a molecule has two electron groups?

Answer 3

linear geometry

180 bond angle

Question 4

What does it mean if a molecule has three electron groups?

Answer 4

trigonal planar

120 bond angles in one plane

Question 5

What do four electrons groups mean?

Answer 5

tetrahedral

109.5 bond angle in 3-D

Question 6

What do five electron groups mean?

Answer 6

trigonal bipyramidal

two axial groups three equatorial groups

120 bond angle between equatorial and 90 between equatorial and axial

Question 7

What are axial and equatorial groups?

Answer 7

axial are vertical (axis)

equatorial are horizontal (equator)

Question 8

What do six electron groups mean?

Answer 8

octahedral

90 bond angle between all groups

Question 9

What are the steps to identifying electron geometry?

Answer 9

draw lewis structure, identify # of e- groups, choose geometry

Question 10

What is the difference between electron geometry and molecular geometry?

Answer 10

e- geometry looks at the arrangement of the electron groups

molcular geometry looks at the arrangment of the atoms only

Question 11

What is electron and molecular geometry for 4 electrons groups and 1 lone pair?

Answer 11

e- geo is tetrahedral

m geo is trigonal pyramidal

Question 12

What is electron and molecular geometry for 4 electron groups and 2 lone pairs?

Answer 12

e- geo is tetrahedral

m geo is bent

Question 13

What do lone pairs do to bond angles?

Answer 13

compress them

less than normal bond angle

Question 14

What are the electron group repulsions from greatest to least?

Answer 14

lone pair/lone pair > lone pair/bonded pair > bonded pair/bonded pair

Question 15

Where does the lone pair go on compounds? Trigonal bipyramidal? Octahedral)

Answer 15

wherever is the furhtest away from the most of the other bonds

equatorial

any position

Question 16

What is electron and molecular geometry for 5 electron groups and 1 lone pairs?

Answer 16

e- geo is trigonal bipyramidal

m geo is seesaw

Question 17

What is electron and molecular geometry for 5 electron groups and 2 lone pairs?

Answer 17

e- geo is trigonal bipyramidal

m geo is t shape

Question 18

What is electron and molecular geometry for 5 electron groups and 3 lone pairs?

Answer 18

e- geo is trigonal bipyramidal

m geo is linear

Question 19

What is electron and molecular geometry for 6 electron groups and 1 lone pairs?

Answer 19

e- geo is octahedral

m geo is square pyramidal

Question 20

What is electron and molecular geometry for 6 electron groups and 2 lone pairs?

Answer 20

e- geo is octahedral

m geo is square planar

Question 21

How can you tell geometry of larger atoms with multiple central atoms?

Answer 21

look at geometry of each individual interior atom

Question 22

What lines do we use to draw tetrahedral structures? What do they mean?

Answer 22

straight line is a bond in the plane of paper

dashed wedge is bond going into paper

black wedge is bond coming out of paper

Question 23

When drawing tetrahedral how many of each type of lines do we use?

Answer 23

2 straight, 1 dashed, 1 solid

dashed and solid next to each other

Question 24

What can a net dipole moment lead to?

Answer 24

entire molecule being polar

Question 25

Can molecules with polar bonds be overall nonpolar? How?

Answer 25

yes

dipoles will cancel out