Ch10 Organic reactions

Question 1

general formula of alkenes

Answer 1

CnH2n

Question 2

5 alkene reactions

Answer 2

combustion
addition
with halogens
with hydrogen
with steam

Question 3

alkene reaction with hydrogen

Answer 3

forms an alkane

occurs in presence of a nickel catalyst

Question 4

Combustion of alkenes

Answer 4

produces carbon dioxide + water

Question 5

Why can’t alkenes be used as fuels

Answer 5

burn with a smokier, yellow flame than alkanes(incomplete combustion)
too reactive(have lots of empty space across the double bond)
release less energy per mole in combustion than alkanes

Question 6

alkene addition reactions

Answer 6

molecules that react with molecule are added across their double bond

Question 7

alkene reaction with halogen

Answer 7

reacts with orange bromine water to turn it colourless

is a test for unsaturated hydrocarbons

Question 8

alkene reaction with water(steam)

Answer 8

forms an alcohol

ethene + steam ⇌ ethanol

Question 9

Functional group of alchohols

Answer 9

-OH

Question 10

General formula of alchohol

Answer 10

CnH2n+1OH

Question 11

Uses of alchohols

Answer 11

fuels
solvents in perfumes, aftershaves and mouthwashes
Alcoholic drinks(ethanol)

Question 12

Display formula of ethanol

Answer 12

H H
l   l
H-C-C-O-H
l   l
H H

Question 13

Reactions of alcohol

Answer 13

combustion
oxidation
with sodium
with water

Question 14

Complete combustion of alcohols

Answer 14

burns with blue clean flame
highly flammable
produces CO2 + H2O

Question 15

Formation of ethanol

Answer 15

sugar solutions are fermented using yeast, producing aqueous solutions of ethanol

Question 16

Reaction of alcohol with sodium metal

Answer 16

produces hydrogen and sodium alkoxide

e.g. sodium + ethanol –> sodium ethoxide + hydrogen

Question 17

Oxidation of alcohols

Answer 17

Forms a carboxylic acid

Question 18

Properties of alcohols

Answer 18

neutral pH
short chain molecule
low boiling point
clean flame
high flammability

Question 19

Carboxylic acids

Answer 19

weak acid (partially ionises in water to form H+ ions)
CH3COOH(aq) ⇌ CH3COO-(aq) + H+(aq)

ethanoic acid is vinegar

Question 20

General formula of carboxylic acid

Answer 20

CnH2nO2

Question 21

Functional group of carboxylic acids

Answer 21

COOH

Question 22

Display formula of

1. methanolic acid
2. ethanoic acid

Answer 22

1. 
          O  
        //
H - C
        \
         O - H 

2. 
      H       O  
       l      //
H - C - C
       l      \
      H       O - H

Question 23

Functional group of esters

Answer 23

-COO-

Question 24

Formation of esters

Answer 24

carboxylic acid + alcohol
uses an acid catalyst
-normally sulfuric acid
also produces water

Question 25

How to create display formula of an ester

Answer 25

1. lose hydrogen from carboxylic acid
2. lose OH from alcohol and move H from left to right side
3. replace H from carboxylic acid with the alcohol

Question 26

Properties of esters

Answer 26

volatile(evaporate easily)
distinctive smells(sweet and fruity)

Question 27

carboxylic acid + carbonate

Answer 27

forms salt + carbon dioxide + water