organic

Question 1

what is the general formula

Answer 1

an algebraic formula that can be used to describe any member in a family of compounds

Question 2

what is the homologous series

Answer 2

a group of compounds with the same functional group and general formula

Question 3

what are the properties of structural isomers

Answer 3

they have the same molecular formula but different structural formula

Question 4

what is a molecular formula

Answer 4

actual number of atoms of each element in a molecule

Question 5

why do atoms in an alkane form tetrahedral shapes

Answer 5

because it has 4 bonds around each atom so bond angle around each atom is 109 as they all repel the same amount

Question 6

how do sigma bonds form in alkanes

Answer 6

2 outer atomic orbitals overlap and combine to form a shared orbital that bonds the two atoms together , the more they overlap the stronger the bond

Question 7

can atoms rotate around a sigma bond

Answer 7

yes

Question 8

what makes a sigma bond strong

Answer 8

High electron density between the two nuclei means strong electrostatic attractions between molecules

Question 9

what causes the low reactivity of alkanes

Answer 9

High bond enthalpy and low polarity of the c-c and c-h bonds so they don’t attract charged particles to react with

Question 10

why do longer chain alkanes have higher boiling points than short chain or branched alkanes

Answer 10

because the longer chain alkanes have a higher molecular surface area and more electrons interacting meaning that there are more London forces

Question 11

why is carbon monoxide lethal

Answer 11

it is better at binding to the haemoglobin in blood than oxygen is

Question 12

what is heterolytic fission

Answer 12

when bond breaks evenly and 1 bonded atom receives both electrons from bonded pair forming a cation and an anion

Question 13

what is homolytic fission

Answer 13

bond breaks evenly and each bonded atom receives 1 electron from the bonding pair forming 2 radicals

Question 14

what is a radical

Answer 14

a species with an unpaired electron

Question 15

what happens during initiation

Answer 15

radicals produced usually through photodissociation

Question 16

what happens during propogation

Answer 16

radicals are created and used up in a chain reaction

Question 17

what happens during termination

Answer 17

radicals are mopped up , the 2 join together and make a stable molecule to terminate the chain reaction

Question 18

why can a mixture of products be created in a free radical reaction

Answer 18

because the reaction can keep going to form other compounds until it is terminated and also can take place at any point on the carbon chain so a mix of isomers may be formed

Question 19

what is the structure of the double bond in alkenes

Answer 19

one sigma bond and one pi bond

Question 20

how is a pi bond formed

Answer 20

when two p orbitals overlap sideways

Question 21

why are pi bonds weaker than sigma bonds

Answer 21

because the electron density is spread out above and below the nuclei so the electrostatic attraction between the nuclei and shared electrons is weaker giving them a low bond enthalpy

Question 22

why are alkenes so reactive

Answer 22

due to the low bond enthalpy of the pi bond , And bond sticking out causing attack from electrophiles

Question 23

why do alkenes form a trigonal planar shape

Answer 23

because the 3 bonds repel each other

Question 24

what are the structures of stereoisomers

Answer 24

molecules that have the same structural formula but different arrangements of the atoms in space

Question 25

what is an electrophile

Answer 25

an electron pair acceptor