alkanes, halogenoalkanes, alkenes and mechanisms

Question 1

What is the ozone?

Answer 1

a form of oxygen, O3

Question 2

What does the ozone do?

Answer 2

absorbs harmful UV rays

Question 3

Please show the equation of the decomposition of CF2CL2 to form a CFC and a radical.

Answer 3

CF2Cl2 –> CF2Cl● + Cl●

Question 4

What are the equations for the destruction of ozone by Cl● free radicals?

Answer 4

Cl● + O3 –> ClO● + O2

ClO● + O3 –> Cl● +2O2

Question 5

What is the overall equation for the decomposition of the ozone layer?

Answer 5

2O3 –> 3O2

Question 6

Why can one free radical destroy so many ozone molecules?

Answer 6

Acts as a catalyst, is not used up in the reaction so one radical can destroy many ozone molecules unless it collides with another radical

Question 7

What roles can OH- have in reactions with halogenoalkanes?

Answer 7

nucleophile or base

Question 8

What does elimination reaction produce?

Answer 8

alkene

Question 9

What is a nucleophile?

Answer 9

a lone pair of electrons donor

Question 10

Why are halogenoalkanes attacked by nucleophiles?

Answer 10

Because C - halogen bonds are polar
C is delta + so the nucleophiles attack it

Question 11

Why does iodopropane react faster with nucleophiles than chloropropane?

Answer 11

Iodine is less electronegative

Question 12

What conditions are need for OH- to act as base?

Answer 12

Hot, ethanolic

Question 13

In a reaction of a 1-bromopropane with KCN what organic product is formed?

Answer 13

butanenitrile

Question 14

What type of isomers are 2,3 - dimethylbutane and 3 - methylpentane?

Answer 14

chain isomers

Question 15

Define electronegativity.

Answer 15

The ability on an atom to attract the shared pair of electrons in a covalent bond towards itself.

Question 16

What are the three types of structural isomers?

Answer 16

C-Chain, position, functional group

Question 17

What are the two types of stereoisomers?

Answer 17

Optical, E-Z

Question 18

What temperature is required for thermal cracking?

Answer 18

900 *C

Question 19

What temperature is required for catalytic cracking?

Answer 19

450 *C

Question 20

What pressure is required for thermal cracking?

Answer 20

70 atm

Question 21

What pressure is required for catalytic cracking?

Answer 21

1-2 atm

Question 22

What catalyst is required for thermal cracking?

Answer 22

none

Question 23

What catalyst is required for catalytic cracking?

Answer 23

zeolites (a type of aluminosilicate catalyst)

Question 24

What is the main product(s) of thermal cracking?

Answer 24

alkenes

Question 25

What is the main product(s) of catalytic cracking?

Answer 25

motor fuels (cyclic alkanes, branched alkanes, aromatics)

Question 26

What are the equations for catalytic converters to remove CO NOx and unburned hydrogencarbons?

Answer 26

2CO + 2NO --> 2 CO2 + N2 C8H18 + 25NO --> 8CO2 + 12 1/2 N2 + 9 H2O

Question 27

What is the initiation step of free-radical substitution of alkanes?

Answer 27

H = halogen H2 --> 2H●

Question 28

What are the two propogation steps for the reaction of methane with a chlorine radical to make CH3Cl

Answer 28

CH4 + Cl● --> ●CH3 + HCl ●CH3 + Cl2 --> CH3Cl + Cl●

Question 29

What's the termination step for CH4 --> CH3Cl

Answer 29

2 ●CH3 --> CH3-CH3

Question 30

Define stereoisomer.

Answer 30

Molecules with the same molecular and structural formulas but a different arrangement of the atoms in space.

Question 31

In electrophilic addition, where should the arrow come from on the alkene?

Answer 31

the C=C