Ch 23 Types ofreactions In organic

Question 1

Mechanism

Answer 1

Detailed step by step description of how the overall reaction occurs

Question 2

Mechanism of mono chlorination of methane: step 1 initiation

Answer 2

Cl•–•Cl—-> Cl• + Cl•
Cl• are free radicals

Uv light provides energy to convert the chlorine molecule into two chlorine free radicals

Question 3

Mechanism of mono chlorination of methane: step 2 propagation

Answer 3

H
Cl•+H-C-H 
            H
                       H
--> H--•Cl + C•
                       H

Question 4

Mechanism of mono chlorination of methane: step 3 propagation

Answer 4

H                            
H-C•+ Cl--Cl•--> 
    H
H-C-Cl + Cl•
    H

Methyl free radical attacks chlorine molecule to create chloromethane and a chlorine atom

Question 5

Mechanism of mono chlorination of methane: step 4 termination

Answer 5

Cl• +Cl•–> Cl2 =chlorine
Cl• +CH3–> Ch3Cl =chloromethane
CH3+Ch3–>C2H6= ethane

Question 6

Free radical

Answer 6

Any atom or group of atoms with an unpaired electro

Question 7

Chain reaction

Answer 7

A reaction that continues on and on because a product from one step of the reaction is a reactant for another step of the reaction

Question 8

Evidence for monocholrination of methane

Answer 8

1) use of UV light causes reaction to start, if UV light is removed the reaction stops
2) traces of C2H6
3) reaction speeds up with the addition of a free radical

Question 9

Substitution reaction

Answer 9

A chemical reaction in which an atom or group of atoms in a molecule is replaced by another atom of group of atoms

Question 10

Uses of halogenated alkanes

Answer 10

Fire extinguishers
Dry cleaning
Making of plastics

Question 11

Esters

Answer 11

Are formed by the reaction of a carboxylic acid with and alcohol

Question 12

Condensation reaction

Answer 12

When two molecules combine to form a larger molecule

Question 13

Addition reaction

Answer 13

Two or more molecules react together to form a single molecule

Question 14

Mechanism of the reaction of ethane and bromine: step 1 polarisation

Answer 14

H   H
   C
   ||   + -Br---Br+
   C
H   H

Question 15

Mechanism of the reaction of ethane and bromine: step 2 heterolytic fission

Answer 15

-Br—Br+

Br has been spit into 2 different species ie Br- and Br+

Question 16

Mechanism of the reaction of ethane and bromine: step 3 carbon ion formation

Answer 16

H   H
   C 
   ||  \   
   ||    +Br        Br-
   ||  /
   C
H   H
              H
----> H-C-Br
                |
               C+
             H  H

Question 17

Mechanism of the reaction of ethane and bromine: step 4 ionic addition

Answer 17

H
           H-C-Br
                |
           H-C-BR
               H

Question 18

Evidence for reaction of theme and bromine

Answer 18

Products
1.2-dibromoethane
1-bromo-2-chloroethane
2-bromoethanol

Question 19

Polymers

Answer 19

Long chain molecules made by joining together many small molecules

Question 20

Polymerisation of ethene

Answer 20

Polythene

Use: plastic bags

Question 21

Polymerisation of chloroethane

Answer 21

Polycholroethene (PVC)

Use: rain coats

Question 22

Polymerisation of propene

Answer 22

Polypropene

Use: plastic buckets

Question 23

Repeating unit (polymer)

Answer 23

Is that part of the polymer whose repetition produces the complete polymer chain except for the end groups

Question 24

Elimination reaction

Answer 24

Where a small molecule is removed from a larger molecule to leave a double bond in the larger molecule