4.1 go over flashcards

Question 1

electrophilic addition reactions can happen to

Answer 1

alkenes

Question 2

what happens when an electrophilic reaction happens to an alkene- why does electrophilic reactions occur to alkenes

Answer 2

the alkene double bond opens up and atoms are added to the carbon atoms

1. electrophilic reactions happen because the double bond had got plenty of electrons, its easily attracted by electrophiles.
2. electrophiles are electron pair acceptors- they’re usually a bit short of electrons, so they’re attracted to areas where there are lost of them about.
3. electrophiles include positively charged ions, like H+ and NO2+, and polar molecules ( since the delta+ atoms is attracted to places with lots of electrons

Question 3

what does adding hydrogen to C=C bonds produce

Answer 3

alkanes

Question 4

adding hydrogen to C=C bonds produce alkenes, what dos it need for this (conditions)

Answer 4

it needs a nickel catalyst and high temperature (150 degrees)

Question 5

halogens react with alkenes to form…

Answer 5

dihaloalkanes

Question 6

halogens react with alkenes to form dihaloalkanes, what sort of reaction is this

Answer 6

electrophilic addition

Question 7

what can u use to test for C=C bonds and what colour does it turn

Answer 7

bromine water is used.

orange-> colourless

Question 8

alcohols can be made by ____ ____ from alkenes

Answer 8

steam hydration

Question 9

when converting alkenes to alcohols, what do u need?

Answer 9

• steam and pressure ( 60-70 atm)

- solid phosphoric (V) acid catalyst

Question 10

why are carbocations more stable with more alkyl groups

Answer 10

because the alkyl groups feed electrons towards the positive charge.

Question 11

what are useful things about polymers

Answer 11

-they’re very unreactive so food doesn’t react with the coasting on pans

Question 12

what are unuseful things about polymers

Answer 12

because of their lack of reactivity, they are difficult to dispose of, most aren’t biodegradable

Question 13

waste plastics can be buried, talk about this option

Answer 13

landfill:
used when the plastic is:
- difficult to separate
- not in sufficient quantities to make separation financially worthwhile 
-too difficult technically to recycle

Question 14

waste plastics can be reused, talk about this option

Answer 14

after sorting into different types:

• some plastics (e.g poly(propene)) can be recycled by melting and remolding them
• some plastics can be cracked into monomers, and these can be used as organic feedstock to make more plastics or other chemicals.

Question 15

waste plastics can be burned, talk about this option

Answer 15

if recycling isn’t possible waste plastics can be burned-and the heat can be used to generate electricity.

• this process needs to be carefully controlled to reduce toxic gasses. e.g polymers containing chlorine (PVC)produce HCl when theyre burned- this has to be removed.
• waste gasses from the combustion are passed through scrubbers which can neutralize gasses such as HCl by allowing them to react with a base

Question 16

in order to decompose biodegradable polymers, what can you do?

Answer 16

Collect and separate them from non- biodegradable polymers- they need to decompose in a compost heap

Question 17

what are biodegradable polymers

Answer 17

polymers that are able to decompose

Question 18

what are photodegradable polymers

Answer 18

polymers that decompose when exposed to sunlight.