The Ozone Story

Question 1

What can be said of most pyramidal molecules?

Answer 1

• they’re polar

* e.g. NH3 - has a lone pair

Question 2

What is true of Hydrogen bonding in molecules?

Answer 2

• when there’s hydrogen bonding then all other (pd-pd and id-id) imb. are present

Question 3

What is true of the C-F bond?

Answer 3

• the bond is too strong to break down in the troposphere or stratosphere so no radicals will be formed

Question 4

Why were the desirable properties of CFC’s?

Answer 4

• they had low toxicity

* they had low flammability

Question 5

Is pressure associated with no. of collisions or energy of particles?

Answer 5

• no. of collisions

Question 6

What are the precipitate colours of the group 7 halides?

Answer 6

• white(chlorine) , cream(bromine), yellow(iodine)

Question 7

With the addition of heat in which order would you expect to see the colours of the group 7 halides?

Answer 7

• yellow, cream then white
• as Iodine has a lower bp. and has weaker bonding. Outermost e- more further away from nucleus therefore loses e- in reactions more easily

Question 8

What is the definition of a nucleophile?

Answer 8

• a negatively charged species that attracts positively charged species

Question 9

Write an equation for the formation of ozone

Answer 9

(O2 + UV —> 2O•)

2O• + O• —> O3

Question 10

Catalysts increase the energy and frequency of colliding molecules.

True or False

Answer 10

• false

* only temperature can affect the energy of particles and the frequency at which they collide

Question 11

In the presence of a catalyst what will happen to a greater proportion of the reactant particles?

Answer 11

• a greater proportion of reacting particles will have sufficient energy to react.
• as catalysts lower the Ea by providing an alternative route allowing for minimum energy of particles to react