Chapter 7: Organic chemistry Flashcards
What is the functional group?
The atoms in a molecule which give it its chemical reactivity (e.g. C=C)
What is a homologous series?
A series of molecules with the same functional group but where each successive member differs by a CH2 unit
What is are the prefixes for members of homologous series?
1 x Carbon= Meth-, 2= Eth-, 3= Prop- 4=But-
What is the functional group for alkanes?
They don’t have one
What is the functional group for alkenes?
C=C
What is the functional group for alcohols?
-OH bound to a carbon
What is the functional group for carboxylic acids?
H-O-C=O (clockwise)
What is the functional group for esters?
O=C-O
What happens when an alkene reacts with a halogen (halogenation)?
The C=C double bond breaks and the carbons bond to halogen atoms
What happens when an alkene reacts with hydrogen (hydrogenation)?
The C=C double bond breaks and each carbon gains an extra hydrogen (nickel catalyst and 150 degrees required)
What happens when an alkene reacts with water (hydration)?
It turns into the equivalent alcohol (H3PO4, high pressure and high temperature required)
What is the naming scheme for esters?
Xanol + Yanoic acid -> Xyl Yanoate + Water
How do alcohols react with water?
Small alcohols dissolve in water to form a neutral solution
What happens when you combust alcohols?
They burn readily with a clean flame, producing CO2 and H2O
How do alcohols react with sodium?
They produce hydrogen
How do alcohols react with oxygen?
They slowly turn into their equivalent carboxylic acid
How do alcohols react with carboxylic acids?
They produce water and an ester (in the presence of an acid catalyst)
How do carboxylic acids react with carbonates?
They make CO2, H2O and the CHxCOO part bonds with the calcium
What is a condensation reaction?
One where water is formed
What are polymers?
Long chain molecules made from joining smaller molecules together
What reactions create polymers?
Addition reactions, condensation reactions
What happens during addition polymerisation?
The C=C double bonds break and the molecules join onto each other
What is the naming scheme for polymers?
Poly + name of repeating unit
What are amino acids?
Molecules that contain both a carboxylic acid functional group and an anime functional group
What do amino acids join up to make?
Polypeptides
What are proteins made of?
Long chains of amino acids joined together in specific sequences
What is starch?
A glucose polymer (so is cellulose)
What are polyesters?
Polymers made when molecules with 2 carboxylic acid functional groups react with molecules with 2 alcohol functional groups
What are polyamides?
Polymers made when molecules with 2 carboxylic acid functional groups react with molecules with 2 anime functional groups (NH2)
What happens during condensation reactions?
Molecules with 2 different functional groups join together and release small molecules such as water
Explain the process of fractional distillation
The crude oil is heated and vaporised. It enters a fractioning tower that is cooler at the top. The hydrocarbon gas rises up the tower and condenses into different substances at different points. Hydrocarbons with small molecules are collected as liquids at the top
Why are long alkanes in less demand?
They are more viscous, less flammable and burn with a smokier flame
What is crude oil?
A fossil fuel found underground in rocks, formed over millions of years from the remains of sea creatures (mostly plankton)
What are alkanes?
A homologous series of saturated hydrocarbons (molecules which only contain single covalent bonds)
What is a homologous series?
A family of compounds all with the same general formula, the same functional group and similar chemical properties
What is the general formula for alkanes?
C(n)H(2n+2)
What is the word equation for the complete combustion of alkanes?
Alkane + Oxygen => Carbon dioxide + water
What is the word equation for the incomplete combustion of alkanes?
Alkane + Oxygen => Carbon monoxide + water
Alkane + Oxygen => Carbon + water
As alkanes get longer, what happens to their boiling point?
It increases
As alkanes get longer, what happens to their viscosity?
It increases
As alkanes get longer, what happens to their flammability?
It decreases
As alkanes get longer, what happens to their flame?
It gets smokier
What is cracking?
The thermal decomposition of long alkanes into shorter alkanes and alkenes
What is catalytic cracking?
Heating the alkanes to vaporise them and then passing them over a hot catalyst
What is steam cracking?
Heating the alkanes to vaporise them, and then mixing them with steam and heating them to a high temperature
What are alkenes?
A homologous series of unsaturated hydrocarbons (molecules which only contain single covalent bonds)
What is the general formula for alkenes?
C(n)H(2n)
What is an addition reaction?
A reaction in which atoms bond to the atoms in a C=C double bond to form a saturated molecule
How is bromine water used to check for C=C double bonds?
The bromine reacts with the C=C double bonds to form saturated molecules, making the usually cloudy bromine water turn clear
What happens when an alkene reacts with oxygen?
It burns with smoky flames due to incomplete combustion
What are the uses of alcohols?
Fuels, solvents, drinks
What are carboxylic acids?
A homologous series of weak acids containing the -COOH functional group
What are esters?
A homologous series of compounds containing the O=C-O functional group
Name some synthetic condensation polymers
Nylon, Kevlar, terylene
Name some natural condensation polymers
Starch, cellulose, proteins
What are carbohydrates?
Biological molecules containing hydrogen, carbon and oxygen
