Chapter 3.5 - Shapes Of Molecules And Ions

Question 1

State the electron pair repulsion theory

Answer 1

Each pair of electrons around an atom will repel all other electron pairs,
The pairs of electrons will therefore take up positions as far apart to minimize repulsion

Question 2

Why are different shapes of molecules formed ?

Answer 2

• shape of a molecule is determined by the number of electron pair around the central atom
• each electron Pair naturally repels each other so that the largest bond angle forms

Question 3

How do lone pairs affect the shape of the molecule ?

Answer 3

Lone pairs push bonding pairs closer together which reduces the bond angle between bonding pairs

Like charges would want to be as far away as possible

Question 4

Explain why CF4 has a bond angle of 109.5

Answer 4

There are 4 bonding pairs of electrons around carbon and no lone pairs , these repel equally and spread as far apart as possible

Question 5

to draw the shape of ClF3 and the shape of CCl2

Include any lone pairs of electrons that influence the shape.

Answer 5

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