(U1) Shapes Of Molecules And Ions

Question 1

When a molecule has 2 bonding pairs and 0 lone pairs, what is its:

• shape
• bond angle
• name an example

Answer 1

• linear shape
• 180º
• BeCl₂ or CO₂

Question 2

When a molecule has 3 bonding pairs and 0 lone pairs, what is its:

• shape
• bond angle
• name an example

Answer 2

• trigonal planar
• 120º
• BF₃

Question 3

When a molecule has 4 bonding pairs and 0 lone pairs, what is its:

• shape
• bond angle
• name an example

Answer 3

• tetrahedral
• 109.5º
• CH₄ or NH₄⁺

Question 4

When a molecule has 3 bonding pairs and 1 lone pair, what is its:

• shape
• bond angle
• name an example

Answer 4

• pyramidal
• 107º
• NH₃ or N₃O⁺

Question 5

When a molecule has 2 bonding pairs and 2 lone pairs, what is its:

• shape
• bond angle
• name an example

Answer 5

• bent
• 104.5º
• H₂O or BrF₂⁺

Question 6

When a molecule has 5 bonding pairs and 0 lone pairs, what is its:

• shape
• bond angle
• name an example

Answer 6

• trigonal bipyramid
• 90º and 120º
• PF₅

Question 7

When a molecule has 3 bonding pairs and 2 lone pairs, what is its:

• shape
• bond angle
• name an example

Answer 7

• T-shaped
• 86º
• BrF₃ or ClF₃

Question 8

When a molecule has 2 bonding pairs and 3 lone pairs, what is its:

• shape
• bond angle
• name an example

Answer 8

• linear
• 180º
• XeF₂ and I₃^-

Question 9

When a molecule has 6 bonding pairs and 0 lone pairs, what is its:

• shape
• bond angle
• name an example

Answer 9

• octahedral
• 90º
• SF₆

Question 10

When a molecule has 4 bonding pairs and 2 lone pairs, what is its:

• shape
• bond angle
• name an example

Answer 10

• square planar
• 90º
• BrF₄^- and XF₄

Question 11

State the VSEPR theory (Valence Shell Electron Pair Repulsion)

State which the order of strengths of repulsion

Answer 11

• Charged clouds arrange themselves to stay as far away from each other as possible
• Lone pair-Lone pair > Lone pair-Bonded pair < Bonded pair-Bonded pair