Organic Chem

Question 1

Define addition reaction

Answer 1

A reaction in which a reactant is added to an unsaturated molecule to make a saturated one

Question 2

Define elimination reaction

Answer 2

A reaction in which a molecule is removed from a saturated mole to make an unsaturated one

Question 3

Define Substitution

Answer 3

A reaction in which an atom is replaced with a different atom

Question 4

Whats heterolytic fission?

Answer 4

Breaking bonds to form a cation and an anion

Question 5

Whats homolytic fission?

Answer 5

Breaking bonds to form 2 radicals

Question 6

Whats a radical?

Answer 6

A species with an unpaired electron

Question 7

Whats an electrophile?

Answer 7

Attract electron

Question 8

Whats dissociation?

Answer 8

HCL into H+ and Cl-

Question 9

Define saturated?

Answer 9

All carbon carbon bonds are single

Question 10

Define hydrocarbon

Answer 10

Compound that contains carbon and hydrogen only

Question 11

Define a sigma bond

Answer 11

Shared electron pair(formed by end on overlap of atomic radius) with the electron denstiry concentrated between two nucleir

Question 12

Why are alkanes unreactive?

Answer 12

C-C bond and C-H bond are strong and have low polarity

Question 13

What are the mechanism stages?

Answer 13

Initiation, Propagation, Termination

Question 14

Whats the initiation step

Answer 14

Halogen breaking to form two radicals

Question 15

Whats needed for the initiation step?

Answer 15

UV light

Question 16

Whats propagation step 1?

Answer 16

Reactant reacts with radical to form H(halogen) and radical

Question 17

What propagation step 2?

Answer 17

Halogen and alkane radical to form alkane(halogen) and halogen radical

Question 18

Whats termination?

Answer 18

Two radicals forming 0 radicals

Question 19

Whats combustion reactions?

Answer 19

Combustion of hydrocarbons is exothermic

Reacted with oxygen to produce H2O and CO2

Question 20

Whats the shape of alkanes?

Answer 20

Shape around each carbon is tetrahedral 109.5

Question 21

How does chain length affect boiling temp?

Answer 21

Increases are there are more bonds to break(induced dipole dipole) intermolecular forces are getting stronger as they’ve got more electrons and surface contact

Question 22

How does branches affect boiling temp?

Answer 22

Decrease as chains cant pack as closely so theres less surface contract so weaker forces

Question 23

What forms a pie bond?

Answer 23

” p orbitals, side ways overlap

Question 24

Whats the bond enthalpy of a sigma and pie bond?

Answer 24

sigma - 348

Pie - 264

Question 25

Whats EZ isomerism?

Answer 25

Z together

E separate

Question 26

Define stereoismoerism

Answer 26

Structual formula to same but different arrangement in space

Question 27

What do you do to decide EZ isomerism?

Answer 27

Atomic number

Question 28

Whats hydrogenation?

Answer 28

Alkenes reacted with hydrogen in precense of nickel catalyst at 150 degress to break double bond

Question 29

What halogenation?

Answer 29

Alkenes react easily with halogens, double bond is broken

Question 30

What test is used to test for C=C bond?

Answer 30

Add bromine water, decolourised if present

Question 31

Whats carbocation?

Answer 31

A species with a positive charge on a carbon atom

Question 32

How do you know if its a major or minor product?

Answer 32

Major if its more stable

Question 33

Whats markownikoffs rule?

Answer 33

Tertiary> secondary> primary

3 C’s bonded to a C> 2C’s> 1C

Question 34

Whats polymerisation?

Answer 34

Breaking a double bond

Question 35

Whats an advantage and disadvantage of using polyalkenes?

Answer 35

Resistant to chemicals but not biodegrable

Question 36

What are two ways of dealing with polymer waste?

Answer 36

Recycling and incineration(heat used to generate electricity