Organic Chemistry Flashcards

Question

Naming alkenes/alkynes

Answer 1

1) The longest carbon chain must contain the double/triple bond 2) number carbon chain from the end closest to double/triple bond 3) add number to name of the carbon the double bond is on 4) add any groups e.g. methyl

Answer 2

Use bromine water Becomes colourless if alkene as bromine reacts with C-C double bond Stays red/brown if alkane as no double bond to react with

Answer 3

A reaction in which hydrogen atoms add to each of the carbon atoms in a double bond of an alkene turning it into an alkane A metal catalyst is used

Answer 4

A ring of carbon atoms with two hydrogen atoms attached to each carbon Formula of C(n)H(2n) They are saturated Add cyclo to the name

Answer 5

Group of aromatic hydrocarbons with a molecular structure containing one or more flat sets of six carbon atoms. Each carbon forms a single covalent bond to the carbons either side and to one hydrogen atom. The final unpaired electron on each carbon is located in the P-orbital that sticks out above and below the plane of the ring. This forms a ring of delocalised electrons. Unsaturated cyclic hydrocarbons Benzene is an example

Answer 6

Molecular formula of C6H6 Ring structure Groups can be added off of benzene

Answer 7

Shows the arrangement of atoms and the bonds

Answer 8

Compounds with the same molecular formula but the atoms are arranged differently which can lead to differences in physical and chemical properties

Answer 9

Chain length isomers Position isomers Functional group isomers

Answer 10

Geometric isomers Optical isomers

Answer 11

Carbon atoms in skeleton arranged differently

Answer 12

Have the same functional groups but attached to different points of the main chain

Answer 13

Have different functional groups E.g. alkane, alkene, alcohol, ether

Answer 14

Have the same structural formula but different in the arrangement of bonds

Answer 15

Differ in the arrangement of the groups attached to the carbons in double bonds

Answer 16

End to end overlap of atomic orbitals All single bonds

Answer 17

When the lobe of one atomic orbital overlaps another Double bonds have a Pi bond as wells as a sigma bond

Answer 18

If the atoms other than hydrogen are all on the same side of the chain they are cis isomers If the atoms other than hydrogen are different sides of the chain they are trans isomers

Answer 19

Hard to figure out which side of which if lots of hydrogens have been substituted for different groups E.g. one side may have carbon and chlorine and the other fluorine and bromine

Answer 20

Used to identify stereoisomers that cannot be defined at cis or trans Isomers identified as either E or Z The higher the atomic number the higher the priority E corresponds to trans form (opposite sides) Z corresponds to cis form (same sides)

Answer 21

Have the same molecular and structural formula but cannot be superimposed as they are mirror images Can occur when an asymmetric carbon (bonded to four different groups) is present so it forms a chiral centre of the molecule

Answer 22

When a carbon atoms is bonded to four different groups

Answer 23

Can rotate the plane of polarised light. Clockwise - positive enantiomer (D form) Anti-clockwise- negative enantiomer (L form) No effect- racemic/racemate

Answer 24

Assign priority to all groups from chiral centre by atomic number View molecule so lowest priority is away from observer Arrow is drawn around in order of priority groups If arrow is clockwise it is R form If arrow is anti-clockwise it is S form

Answer 25

Free radical substitution

Answer 26

Electrophilic addition

Answer 27

1) initiation 2) propagation 3) termination

Answer 28

UV light absorbed by halogen molecule to provide energy to break the bond. One electron goes to each halogen and forms two free radicals (homolytic fission)

Answer 29

Single bond breaks, one electron to each molecule. Shown by a curly half arrow head. Forms two products that are the same

Answer 30

Breaking of bonds. One atoms gains both electrons. So atom is now negatively charged and other is positively charged. Two different products

Answer 31

A highly reactive species with a single unpaired electron. Electron is represented by a dot.

Answer 32

A halogen radical reacts with a methane molecule. This removed hydrogen from the methane and forms a methyl radical and hydrogen chloride. The methyl radical can then bond with a halogen molecule forming another halogen radical and halogenmethane. During this process the total number of radicals remains the same.

Answer 33

Total number of free radicals decreases. Free radicals can join together to create stable molecules. Methyl to halogen Halogen to halogen Methyl to methyl

Answer 34

Hard to separate the mixture of products formed

Answer 35

Halogenoalkane molecules where all the hydrogen atoms have been replaced by fluorine or chlorine.

Answer 36

Destroy the ozone layer (O3) due to free radical substitution

Answer 37

Electrophilic addition. As the double bond is an area of high negative charge making it very reactive.UV light is not needed.

Answer 38

Electron pair acceptor. They accept a pair of electrons to form a covalent bond. They are electron deficient. Represented as E+.

Answer 39

Electron pair donator. They donate a pair of electrons to form a covalent bond. They can be represented by Nu:

Answer 40

The double bond in the alkene is electron dense (negatively charged). The electrophile is attracted to this. The electrophile breaks down and undergoes heterolytic fission so both the electrons go to the atom not attaching to the double bond. Finally the atom that accepted the electrons bonds with the other carbon to form a dative covalent bond.

Answer 41

Homologous series of organic compounds with the general formula CnH2n+1OH Names end in ol Functional group is OH

Answer 42

Name of length of carbon chain with suffix -ol If there are 3 or more carbons positional isomerism can be displayed The carbon number the OH is attached to is written before -ol

Answer 43

Much higher boiling point than alkanes Boiling point increases as carbon chain length increases Most are liquid at room temperature

Answer 44

The electronegative oxygen atom in the hydroxyl group means alcohols are polar so can take part in hydrogen bonding meaning the boiling point will be higher than that of an alkane Hydrogen bonding also means alcohols can mix with water

Answer 45

Hydration of an alkene add water to alkene in form of steam with a phosphoric acid catalyst. Temperature must be 570K and pressure 60-70 atm Fermentation Glucose + yeast —\> ethanol + carbon dioxide Anaerobic conditions Temperature 25-35c Yeast dies when ethanol concentration reaches around 15% Slow process

Answer 46

Renewable resources used Less energy used

Answer 47

High yield of ethanol Atom economy of 100% Fast reaction Can be done continuously

Answer 48

Primary: have one R group attached to the carbon to which the OH group is attached Secondary: have two R groups attached to the carbon to which the OH group is attached Tertiary: have two R groups attached to the carbon to which the OH group is attached

Answer 49

Carbonyl group C=O

Answer 50

Carbonyl group at the end is an aldehyde. So it has at least one hydrogen attached to it Carbonyl group in the middle is a ketone so has two carbons attached to it

Answer 51

Named using carbon chain length and then the suffix -al Carbons numbered starting with carbonyl group as 1

Answer 52

Using length of carbon chain and suffix -one Carbon number of carbonyl group placed before suffix

Answer 53

Polar Positive charge on the carbon makes it open to attacked by nucleophiles Aldehydes and ketones can be reduced, forming alcohol Aldehydes can be oxidised to carboxylic acids

Answer 54

Small ones are soluble in water due to hydrogen bonding between a lone pair on the oxygen of the carbonyl group and the hydrogen of water As size increases solubility decreases due to interference in hydrogen bonding by the hydrocarbon tails Have mid range boiling points as have van der Waals forces AND the polar carbonyl group means dipole-dipole interactions are present

Answer 55

Alkanes have the lowest as only van der Waals forces are present Aldehydes & ketones are higher as they also have dipole-dipole interactions as the carbonyl group is polar Alcohols are higher still as they also have hydrogen bonding Carboxylic acids are highest as they have more hydrogen bonds

Answer 56

Primary alcohols can be oxidised by an oxidising agent such as an aqueous solution of acidified potassium dichromate which changes colour from orange to green. Water is also produced in the reaction.

Answer 57

Secondary alcohols can be oxidised by an oxidising agent such as an aqueous solution of acidified potassium dichromate. Water is also produced

Answer 58

The lack of hydrogen atoms on the carbon atom to which the hydroxyl group of attached

Answer 59

Tollens’ reagent: Sodium hydroxide + aqueous silver nitrate. This forms a brown precipitate of silver nitrate (Ag2O). Aqueous ammonia is added until precipitate dissolves and a solution of the silver amine [Ag(NH3)2]+ is formed. A silver colour is formed if aldehydes are present No colour change if ketone Benedict’s solution: An alkaline solution containing copper ions. When heated with an aldehyde the Cu2+ complex ion acts as an oxidising agent and the blue turns to red No colour change if ketone

Answer 60

Carboxyl group (COOH) attached to terminal carbon

Answer 61

Using length of carbon chain and suffix -oic acid

Answer 62

Polar due to presence of two electronegative oxygen atoms and a partially charged carbon and hydrogen atom Can take part in: Neutralisation- carboxylic acid loses a proton to from a carboxylate salt Nucleophillic substitution- partially positive carbon is attacked by nucleophile resulting in substitution of OH group Esterification- reaction with an alcohol for form an ester

Answer 63

Solubility depends on side. The smaller the compound the higher the solubility. Carboxylic acids are higher due to more hydrogen bonds present

Answer 64

Primary alcohols are reacted with an excess of oxidised agent and refluxed. Primary alcohol—\>aldehyde —\>carboxylic acid Reflux position is the condenser tube vertical. The condenser tube is continuously surrounded by cold water. As aldehyde is produced it evaporates but the cold water then cools it back to a liquid so it can go back to undergo second oxidisation Reflux definition: the continuous evaporation and condensation of a volatile substance without loss of any product

Answer 65

-COO- Carbon double bonded to one oxygen and single bonded to another oxygen

Answer 66

Esterification: When alcohol is warmed with a carboxylic acid in the presence of an acid catalyst. A water molecule is removed Concentrated sulfuric acid is often used as the catalyst The O-H bond of alcohol is broken and water formed with the OH from the carboxylic acid group and the H in the alcohol group Carboxylic acid + alcohol -\> ester + water

Answer 67

First part from the alcohol used with -yl e.g ethyl Second part from carboxylic acid used with -anoate e.g. ethanoate X-yl X-anoate

Answer 68

Chemical reaction using water to break down bonds of a substance Esters can be hydrolysed by refluxing with either an acid or alkali With an acid it reverses the ester back to an alcohol and carboxylic acid With an alkali it hydrolysed to an alcohol and sodium salt of the acid

Answer 69

Nitrogen containing organic compounds derived from ammonia where one or more of the hydrogen atoms has been replaced by an alkyl or aryl group

Answer 70

Primary: where one hydrogen from ammonia is substituted with carbon Secondary: where two hydrogens from ammonia are substituted Tertiary: where all three hydrogen atoms are substituted Quaternary: where four carbons are attached to the nitrogen, using ammonia’s lone pair of electrons

Answer 71

Use the length of the carbon chain and use suffix -amine E.g. methylamine If other functional groups are present then the amino- prefix is used E.g. 2-aminoethanoic acid

Answer 72

Solubility: shorted chains are soluble in water as the lone pair of electrons in the nitrogen atom allows them to form hydrogen bonds with water molecules Larger amines are less soluble as the larger R groups interfere with hydrogen bonds Boiling points: primary amines have higher boiling points that alkanes as they can form hydrogen bonds . Secondary amines having slightly lower boiling points as the nitrogen forming the hydrogen bond is in the middle of the chain and this slightly reduces the strength of the dipole Tertiary amines have even lower boiling points

Answer 73

Products of reactions between carboxylic acids and amines An amide and water is produced Contain functional group CONH Amino acids contain both amine and carboxylic acid functional groups. They can react together to form an amide link (peptide bond)