C6.2 Organic Chemistry Flashcards
What are hydrocarbons
compounds that contain carbon and hydrogen only
Alkanes are hydrocarbons, why do they form a homologous series
They have the same general formula.
They are saturated
What is the general formula for alkanes
CnH2n+2
Name the first 4 straight chain alkanes
Methane, Ethane, Propane, Butane
What are the products when alkanes undergo combustion
carbon dioxide and water
what is formed when alkanes undergo incomplete combustion
water, carbon monoxide and carbon (soot)
what features do alkenes have in common
They have C-C double bond and are unsaturated
Give the general formula for alkenes
CnH2n
Name the first 4 alkenes
Ethene, propene, butene, pentene
What is an addition reaction
An atom/group of atoms combine with a molecule, and no other products are formed
What do you see when bromine water is added to alkenes
It goes colourless from orange - brown
How do you form alkanes from alkenes
Add hydrogen in the presence of a Nickel catalyst
What is the functional group present in alcohols and name it
-OH
Hydroxyl group
What do names of alcohols end in
‘ol’
Name the first 4 alcohols
methanol, ethanol, propanol, butanol
What is formed when alcohols undergo combustion
Carbon dioxide and water
What is the functional group present in carboxylic acids
Carboxyl group
-COOH
What is the general formula for carboxylic acids
CnH2n+1COOH
Name the first 4 carboxylic acids
methanoic acid, ethanoic acid, propanoic acid, butanoic acid
How are carboxylic acids made
when alcohols react with oxidising agents in the presence of dilute sulfuric acid
What is formed when carboxylic acids react with metals
Salt and hydrogen
What is formed when carboxylic acids react with alkalis and bases
Salt and water
How are carboxylic acids made
When alcohols react with oxidising agents such as potassium manganate (V11) solution
Explain why crude oil is a finite resource
It is non-renewable and is being used up faster than it is being formed
Describe and explain fractional distillation
Separating mixture of liquids with different boiling points into different fractions
What is cracking
Breaking down large alkanes to smaller alkane and alkene molecules
What are the conditions to carry out cracking
High temperature and need a hot catalyst of alumina or silica
Why is cracking done ?
It helps to match the supply needed of the smaller, more useful molecules in demand
What is addition polymerisation
When monomers add together to form a long chain polymer
Give some examples of polymers
polyethene, polypropene, polychloroethene
What are the conditions to carry out addition polymerisation
High pressure and a catalyst
What are the monomers of DNA
Nucleotides
What does a nucleotide consist of
phosphate, deoxyribose, base
What are the monomers of a protein
Amino Acids
What are the monomers of a carbohydrate
sugars
Name the 4 bases found in DNA
Adenine, Thymine, Cytosine, Guanine
What happens in a condensation reaction
2 molecules react together to form one larger molecule and one smaller molecule
what is an amino group
-NH2
What is a carboxyl group
-COOH
What is an ester group
-COO-
What is an Amide group
-CONH-
6 marker question:
Compare the structure of DNA, Proteins and Carbohydrates.
In your answer, include the similarities and differences between them.
They are polymers. They are made up of monomers.
DNA monomers are nucleotides (Phosphate, sugar-deoxyribose, organic base). Proteins are made from amino acids. carbohydrates are made from simple sugars (glucose, & sucrose)
DNA contains four different monomers / nucleotides. Proteins contain about 20 different monomers / amino acids - higher
Sucrose contains two different simple sugars / glucose and fructose -higher
Write a word equation for making polyamide
diamine + dicarboxylic acid polyamide + water
What are polyesters made from
A carboxylic acid with two carboxyl groups also known as dicarboxylic acid.
An alcohol with two hydroxyl groups also known as diol
How are proteins formed?
Proteins are condensation polymers formed from amino acids.
Amino acids have two different functional groups: Amino and a carboxyl group
What is the fuel in a hydrogen oxygen fuel cell
The hydrogen-oxygen fuel cell uses hydrogen as its fuel
What is produced as a product in the hydrogen oxygen fuel cell
Water
Write the reaction at the anode
H2(g) → 2H+ (aq) + 2e-
Write the reaction at the cathode
4H+(aq) + O2 (g) + 4e- → 2H2O(g)
State some advantages of fuel cells
They have no moving parts
They are compact.
They are lightweight.
Zero emissions of CO2 from cars (H2O only product)
Easy access to hydrogen and oxygen from decomposition of water
What are the disadvantages of fuel cells
The method we currently use to produce hydrogen uses fossil fuels which produce pollutants and are running out.
Fuel cells often use poisonous catalysts which have to be disposed of safely when the fuel cell reaches the end of its life
