Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

chemistry > topic 6C > Flashcards

topic 6C Flashcards

You may prefer our related Brainscape-certified flashcards:
Periodic Table flashcards Chemistry 101 flashcards AP® Chemistry flashcards Organic Chemistry 101 flashcards
1
Q

general formula for alkenes

A

CnH2n

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

bonding in alkenes

A
  • C=C double covalent bond consists of one sigma and one pi bond
  • pi bonds are exposed and have higher electron density
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

formation of sigma (σ) bond

A
  • one sp2 orbital from each carbon overlap to form a single C-C bond (σ)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

formation of pi (π) bond

A
  • bond is formed by sideways overlap of two p orbitals on each carbon atom forming a π bond above and below the plane of the molecule
  • restricted rotation about pi bond
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what is an electrophile

A

an electron pair acceptor

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

reaction of alkenes with hydrogen
- group change
- reagent
- conditions
- type of reaction

A
  • group change: alkene to alkane
  • reagent: hydrogen
  • conditions: nickel catalyst
  • type of reaction : addition/reduction
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

electrophilic addition: reaction of alkenes

A
  • sigma bond is weaker than a pi bond so less energy is needed to break a sigma bond.
  • the bonds in alkenes are areas with high electron density.
  • this is accesible to electrophilic attack by electrophiles
  • alkenes udnergo addition reactions
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

reaction of alkenes with bromine/chlorine
- group change
- reagent
- conditions
- mechanism
- type of reagent
- type of bond fission

A
  • group change : alkene to dihalogenoalkane
  • reagent : bromine dissolved in organic solvent
  • conditions : room temp
  • mechanism : electrophilic addition
  • type of reagent: electrophile
  • type of bond fission : heterolytic
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

reaction of alkenes with hydrogen bromide
- group change
- reagent
- conditions
- type of reaction

A
  • group change : alkene to halogenoalkane
  • reagent: HCl or HBr
  • conditions: room temp
  • mechanism: electrophilic addition
  • reagent type: electrophile
  • bond fission: heterolytic
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

reaction of alkenes with potassium manganate (VII)
- group change
- reagent
- conditions
- type of reaction
- observation

A
  • group change: alkene to diol
  • reagent: KMnO4 in acidified solution
  • conditions: room temp
  • type of reaction: oxidation
  • observation: purple to colourless
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

reaction of alkenes with bromine water
- reagent
- conditions
- type of reaction
- observation

A
  • reagent: bromine dissolved in water
  • conditions: room temp
  • type of reaction: addition
  • observation: orange to colourless
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

hydration of alkenes to form alcohols

A
  • reacted in water in the presence of an acid catalyst
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

essential conditions for the hydration of alkenes

A
  • high temperature 300 to 600°C
  • high pressure 70 atm
  • catalyst of conc H3PO4
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what do high pressures mean

A
  • it cannot be done in the lab; must be done industrially
  • there are no waste products so there’s a high atom economy
  • separation of products is easier and cheaper
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what is heterolytic bond fission

A

heterolytic bond fission of a covalent bond results in the formation of ions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

addition polymerisation

A

alkenes form polymers through addition polymerisation

17
Q

methods of disposal of waste polymers - recycling

A
  • saves raw materials - nearly all polymers are formed from compounds produced from crude oil - saves precious resources
  • polymers need collecting/sorting - expensive (energy and manpower)
  • polymers can be recycled into the same type - careful separation needs to be done
  • thermoplastic polymers can be melted down and reshaped
18
Q

methods of disposal of waste polymers - incineration

A
  • rubbish is burnt and energy produced is used to generate electricity
  • some toxins can be released on incineration - can lead to formation of toxic, acidic waste products
  • modern incinerators can burn more efficiently and most toxins can be removed
  • volume of rubbish is greatly reduced
19
Q

methods of disposal of waste polymers - feedstock for cracking

A
  • polymers can be cracked into small molecules which can be used to make other chemicals and new polymers
  • saves raw materials
20
Q
A

chemistry (28 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions