Structure and Bonding 3 - Shapes of Molecules and States of Matter

Question 1

state the electron repulsion theory (VESPR)

Answer 1

lone pair:lone pair > lone pair: bonding pair > bonding pair:bonding pair repulsions
(lp:lp > lp:bp > bp:bp)

Question 2

how do you deduce the number of electrons for the shape of an ion?

Answer 2

same method for molecule but
+1 ion = lose one electron
-1 ion = gain one electron
etc
make sure to put charge around molecule once drawn!!

Question 3

draw the structure for 2bp 0lp, name it and label the angle

Answer 3

name = linear
angle = 180°

Question 4

draw the structure for 3bp 0lp, name it and label the angle

Answer 4

name = trigonal planar
angle = 120

Question 5

draw the structure for 2bp 1lp, name it and label the angle

Answer 5

name = bent
angle = 118

Question 6

how many degrees does one lone pair contribute to via repulsion?

Answer 6

2 degrees for every lone pair

Question 7

draw the structure for 4bp 0lp, name it and label the angle

Answer 7

name = tetrahedral
angle = 109.5

Question 8

draw the structure for 3bp 1lp, name it and label the angle

Answer 8

name = trigonal pyramidal
angle = 107

Question 9

draw the structure for 2bp 2lp, name it and label the angle

Answer 9

name = bent
angle = 104

Question 10

draw the structure for 5bp 0lp, name it and label the angle

Answer 10

name = trigonal bipyramidal
angle = 90 and 120

Question 11

draw the structure for 6bp 0lp, name it and label the angle

Answer 11

name = octahedral
angle = 90

Question 12

draw the structure for 4bp 2lp, name it and label the angle

Answer 12

name = square planar
angle = 90

Question 13

draw the structure for 5bp 1lp, name it and label the angle

Answer 13

name = square pyramidal
angle = 90

Question 14

for the following, state whether it is an exothermic or endothermic process and why?
melting
freezing
evaporation
condensation

Answer 14

melting = endothermic, energy is transferred FROM the surroundings
freezing = exothermic, energy is RELEASED to the surroundings
boiling = endothermic, energy is transferred FROM the surroundings
condensing = exothermic, energy is RELEASED to the surroundings

Question 15

describe the three states of matter in terms of volume and shape

Answer 15

solids have a fixed volume and shape
liquids have a fixed volume but no fixed shape
gases have no fixed volume or shape