Alkenes

Question 1

What is stereoisomerism?

Answer 1

Compounds with the same structural formula but the atoms are pointing in a different direction in space

Question 2

What is E/Z isomerism?

Answer 2

A type of isomerism and a type of stereoisomerism that occurs in alkenes due to no rotation in a double carbon bond

Question 3

In which type of compounds does E/Z isomerism occur?

Answer 3

Alkenes

Question 4

Why can’t alkenes rotate like alkanes?

Answer 4

There is no rotation in a double carbon bond

Question 5

What is the Z isomer?

Answer 5

Isomer where both atoms are on the ‘same’ side of the carbon

Question 6

How do you determine if an isomer is Z?

Answer 6

If the atoms bonded to the carbon with the highest priority (highest atomic number) are on the same side

Question 7

What is the E isomer?

Answer 7

The isomer where the highest priority atoms are on opposite sides

Question 8

How do you name an E/Z isomer?

Answer 8

Put a ‘Z’ or ‘E’ at the front when naming the alkene, treating E or Z like a number with a dash (-) after it

Question 9

Provide an example of an alkene that can exist as E/Z isomers.

Answer 9

But-2-ene can exist as Z-but-2-ene or E-but-2-ene

Question 10

What condition must be met for E/Z isomers to occur?

Answer 10

Both carbons in the double carbon bond must have two different atoms or groups attached

Question 11

True or False: All alkenes have E/Z isomers.

Answer 11

False

Question 12

What is addition polymerisation?

Answer 12

Addition polymerisation is the process where monomers are joined together to form a polymer.

Question 13

What is a polymer?

Answer 13

A polymer is a large molecule made up of many repeating units called monomers.

Question 14

What happens during the formation of an addition polymer?

Answer 14

During the formation of an addition polymer, the double bonds in alkenes break and the alkenes join together in a chain.

Question 15

What is represented by the notation C=C?

Answer 15

C=C represents the double bond between carbon atoms in alkenes.

Question 16

What does the symbol ‘n’ signify in the context of polymers?

Answer 16

‘n’ signifies the number of alkenes that are joined together to form the polymer.

Question 17

How do you denote a polymer made from an alkene?

Answer 17

To denote a polymer made from an alkene, you write the name of the polymer in front of the alkene.

Question 18

What is the environmental impact of recycling polymers?

Answer 18

Recycling reduces the environmental impact of discarded polymers by preventing them from ending up in landfills.

Question 19

What are the steps involved in recycling polymers?

Answer 19

Discarded polymers are sorted, chopped, washed, dried, and then melted.

Question 20

What happens to recycled polymers after processing?

Answer 20

The recycled polymer is then sold for further use.

Question 21

What is a hazard associated with recycling PVC?

Answer 21

Recycling PVC can release hydrogen chloride, a corrosive gas.

Question 22

Why are some polymers difficult to recycle?

Answer 22

Some polymers are difficult to recycle because they are derived from petroleum.

Question 23

What is one method of waste management for non-recyclable polymers?

Answer 23

Non-recyclable polymers can be incinerated to produce heat and generate steam.

Question 24

What can be generated from incinerating waste polymers?

Answer 24

Incinerating waste polymers can generate electricity for the national grid.

Question 25

What is feedstock recycling?

Answer 25

Feedstock recycling is a chemical and thermal process that reclaims monomers, gases, or oil to reuse and make new products from waste polymers.

Question 26

How can feedstock recycling benefit crude oil production?

Answer 26

The materials reclaimed through feedstock recycling can be used as raw materials for the production of new polymers in refineries.

Question 27

What is a major advantage of feedstock recycling?

Answer 27

A major advantage of feedstock recycling is that it is able to handle unsorted and unmixed polymers.

Question 28

What are biodegradable polymers?

Answer 28

Biodegradable polymers are broken down by microorganisms into water, carbon dioxide, and organic compounds.

Question 29

What are biodegradable polymers typically made from?

Answer 29

They are usually made from starch or cellulose, or contain additives that alter the structure of traditional polymers.

Question 30

What are compostable polymers?

Answer 30

Compostable polymers leave no toxic residue and are based on polylactic acid.

Question 31

What are some examples of products made from compostable polymers?

Answer 31

Examples include plates and cups made of sugar cane fiber, which are replacing traditional plastic products.

Question 32

What are photo degradable polymers?

Answer 32

Photo degradable polymers are plant-based polymers that can degrade when exposed to light.

Question 33

How do photo degradable polymers start degradation?

Answer 33

They contain bonds that are weakened by absorbing light to start degradation.

Question 34

What are light-absorbing additives used for?

Answer 34

Light-absorbing additives are used in the development of photo degradable polymers.

Question 35

What are the four reactions that occur with alkenes

Answer 35

Hydrogenation, Halogenation, Hydrogenation, Hydration reactions

Question 36

What conditions do you need for hydrogenation, what does this make

Answer 36

Needs to be passed through a nickel catalyst at a temperature of 150°C. It is used to make saturated oil (margarine)

Question 37

What are the conditions needed for the hydration of alkenes

Answer 37

Alkenes react with steam. In the presence of a phosphoric acid (H₃PO₄)with high temp of 300°C and 60atm

Question 38

What are the dangers of consuming saturated fats

Answer 38

They cause heart disease