Bonding Exam Style Q

Question 1

What is the bond angle and shape of a molecule with 2 bonding pairs and 0 lone pairs and why?

Answer 1

-180 degrees
-Linear
-2 bonding pairs, 0 lone pairs → Electron pairs repel equally → Form a straight-line shape.

Question 2

What is the bond angle and shape of BF₃ and why?

Answer 2

-120 degrees
-Trigonal planar
-3 bonding pairs, 0 lone pairs → Bonding pairs repel equally → Form a flat triangular shape.

Question 3

What shape does CH₄ have, and why?

Answer 3

-109.5 degrees
-Tetrahedral
-4 bonding pairs, 0 lone pairs → Bonding pairs repel equally in 3D → Form a tetrahedral shape.

Question 4

Why is the bond angle of NH₃ (~107°) smaller than in a tetrahedral molecule like CH₄?

Answer 4

• NH3 is Trigonal Pyramidal
  -3 bonding pairs, 1 lone pair → Lone pair repels bonding pairs more strongly → Reduces bond angle.

Question 5

Why is the bond angle of H₂O (~104.5°) even smaller than NH₃?

Answer 5

-H20 is Bent
-2 bonding pairs, 2 lone pairs → Lone pairs repel even more than bonding pairs → Compresses bond angle.

Question 6

Why does PCl₅ have two different bond angles (90° and 120°)?

Answer 6

• It is Trigonal Bipyramidal
  -5 bonding pairs, 0 lone pairs → Three equatorial bonds at 120°, two axial bonds at 90°.

Question 7

Why does SF₄ have a see-saw shape instead of trigonal bipyramidal?

Answer 7

-Bond angles of 86 and 118 degrees
-4 bonding pairs, 1 lone pair → Lone pair takes an equatorial position → Distorts the shape.
-Lone pair repels axial bonds, reducing bond angles.

Question 8

What is the bond angle and shape of SF₆?

Answer 8

-90 degrees
-Octahedral
-6 bonding pairs, 0 lone pairs → Bonding pairs repel equally → Forms a symmetrical octahedron.

Question 9

Why is XeF₄ square planar instead of tetrahedral?

Answer 9

-Bond angle of 90 degrees
-4 bonding pairs, 2 lone pairs → Lone pairs position opposite each other → Cancel out dipoles → Flat square shape.