organic chemistry

Question 1

What is a hydrocarbon?

Answer 1

A hydrocarbon is a molecule made up of only hydrogen + carbon

Question 2

why type of bonds do alkanes have?

Answer 2

single covalent bonds

Question 3

what is the alkane formula

Answer 3

CnH2n+2

Question 4

how many bonds can carbon form?

Answer 4

4 bonds

Question 5

what is CH4 called ?

Answer 5

methane

Question 6

what is a homologous series?

Answer 6

a group of hydrocarbons with a similar function group and therefore similar properties e.g alkAnes, alkEnes, alcOHOLS

Question 7

what are the first 6 alkanes

Answer 7

1= methane 
2= ethane
3=propane
4=butane
5=pentane
6=hexane

Question 8

what is a structural isomer?

Answer 8

molecules that have the same molecular formula but a different structural formula i.e the order the atoms are connected to the chain is differnt.

Question 9

the longer the hydrocarbon the_____ the surface area

Answer 9

bigger

Question 10

the larger the surface area the______ the number of intermolecular forces.

Answer 10

higher

Question 11

the greater the number of intermolecular forces the _____ the energy required to break them.

Answer 11

higher

Question 12

the more energy required to break the intermolecular forces the ____ boiling point

Answer 12

higher

Question 13

what type of bond is present in an alkene

Answer 13

a double bond

Question 14

what is the general formula for an alkene ?

Answer 14

CnH2n

Question 15

if the double bond was on the first carbon of an alkene with 4 carbons what would you name it?

Answer 15

but-1-ene

Question 16

are alkanes saturated and why?

Answer 16

alkanes are saturated because every spare bond is attached to a hydrogen

Question 17

are alkenes saturated and why?

Answer 17

alkenes unsaturated because they contain a double bond and therefore have less carbon atoms

Question 18

what is a symmetric alkene?

Answer 18

semetric alkenes have the same groups on each side of a double bond

Question 19

what is an asymmetric alkene

Answer 19

asymmetric alkenes have different groups on each side of the double bond.

Question 20

what is a geometric isomer in an alkene ?

Answer 20

geometric isomers is where there are the same groups on each side of them double bond however they have a different arrangement.

• this is because the double bond does not rotate
• same structural formula

Question 21

what is a cis geometric isomer ?

Answer 21

cis is where the alkene has matching groups on the same side of the bond (if you draw out the skeletal formula it makes a c shape)

Question 22

what is a trans geometric formula?

Answer 22

trans is where the matching groups are on opposite sides of the bond

Question 23

z

Answer 23

• together

‘zame zide’

Question 24

E

Answer 24

separate

Question 25

tetrahedral , area of electron density and angle

Answer 25

4 and 109.5 degrees

Question 26

trigonal planar ,area of electron density and angle

Answer 26

3 and 120

Question 27

linear ,area of electron density and angle

Answer 27

2 and 180

Question 28

where are sigma bond found and what are they

Answer 28

they are found in alkanes (single bonds)

Question 29

which is the strongest, sigma or pi bonds?

Answer 29

sigma bond because there is a greater overlap

Question 30

which is shortest a double bond or a single bond

Answer 30

a single bond

Question 31

electrophile

Answer 31

a molecule or atom which is attracted to a negative charge and can accept a lone pair of electrons to form a covalent bond

Question 32

electrophilic addition

Answer 32

atoms or ions are added across the bond. no atoms are lost. this can happen because the carbon is double bonded double bond opens up to allow a molecule to join on.

Question 33

carbocation

Answer 33

ion with a positively charged carbon atom

Question 34

polarised

Answer 34

when a molecule becomes positive at one end and negative at the other

Question 35

curly arrow

Answer 35

shows the movement of an electron pair

Question 36

what is a stable carbocation

Answer 36

a carbon cation which is attached to the most carbon atoms (has the most electrons donated)

Question 37

what do alkyl groups do? (carbon groups)

Answer 37

they have an electron donating effect

Question 38

electron configuration

Answer 38

1s, 2s, 2p, 3s, 3p, 4s, 3d

Question 39

p orbitals

Answer 39

2px 2py 2pz

Question 40

max electrons in s

Answer 40

2

Question 41

max electrons p holds

Answer 41

6

Question 42

max electrons d holds

Answer 42

10

Question 43

Each hybrid orbital contains 2 electrons ready for bonding true or false

Answer 43

true

Question 44

Each hybrid orbital contains 2 electrons ready for bonding true or false

Answer 44

false only 1

Question 45

P orbitals that are not hybridised can overlap to form pi bonds true or false

Answer 45

true

Question 46

The number of hybrid orbitals formed is always 1 more than the number of orbitals used true or false

Answer 46

false, the same number

Question 47

The superscript in sp3 tells you the number of s orbitals used to make the hybrid orbital. true or false

Answer 47

false the p orbitals

Question 48

Carbons with 3 areas of electron density form linear shapes. true or false

Answer 48

false trigonal planar

Question 49

how many orbitals in a tetrahedral molecule | hybridisation

Answer 49

one of the s orbitals and three of the p orbitals combine to form four hybrid sp orbitals making 4 sigma bonds

Question 50

how many orbitals in a trigonal planar molecule | hybridisation

Answer 50

one of the s orbitals and two of the p orbitals combine to form three hybrid sp2 orbitals creating 3 sigma bonds.

Question 51

how many orbitals in a linear molecule | hybridisation

Answer 51

one of the s orbitals and one of the p orbitals combine to form 2 hybrid sp orbitals creating 2 sigma bonds

Question 52

What are the prefixes for branched alkanes with a chain length of 1 - 4 carbons? Eg methyl, ...

Answer 52

ethyl propyl butyl

Question 53

What is a cycloalkane?

Answer 53

alkanes that have carbon atoms attached in a ring.

Question 54

how do you test for an alkene ?

Answer 54

bromine water

Question 55

What is electron pair repulsion theory?

Answer 55

The principle that electron pairs around a central atom tend to orient themselves as far apart as possible.

Question 56

what are the three steps of a free radical ?

Answer 56

initiation, propagation, termination

Question 57

conditions for free radical substitution

Answer 57

needs uv light to start the reaction (initiation stage)

Question 58

What is heterolytic (bond) fission?

Answer 58

the breaking of a covalent bond in such a way that one atom gets both of the shared electrons - creates a + and a - ion

Question 59

What is homolytic (bond) fission?

Answer 59

Homolytic fission is where each atom of the bond keeps an electron each resulting in species called free radicals

Question 60

What is a polymer?

Answer 60

a long chain molecule that is formed from small molecules linking together

Question 61

What is the name for the mechanism for making polymers?

Answer 61

polymerization

Question 62

What is cracking?

Answer 62

Cracking is a reaction in which larger saturated hydrocarbon molecules are broken down into smaller, more useful hydrocarbon molecules

Question 63

What are the two types of cracking?

Answer 63

Catalytic cracking uses a temperature of approximately 550°C and a catalyst known as a zeolite which contains aluminium oxide and silicon oxide. Steam cracking uses a higher temperature of over 800°C and no catalyst.