Monomers and Polymers

Monomer- a single unit of a polymer

polymer- is made of many monomers

ethene--> polyethene

propane---> polypropene

styrene---> polystyrene

monomers must have a double bond to become a polymer

polythene E.g- plastic bags

Unlimited prat of polythene chain

Addition polymerization- this is when a polymer is turned into a polymer

Propene into Polypropene

Styrene to Polystyrene

3.3 I can recall the general formula and displayed formulae of alkanes

Methane
Ethane
Propane
Butane
Pentane

3.4 I can recall the products of complete and incomplete combustion of alkanes

1.       Saturated hydrocarbons are called Alkanes 

2.       Small chain Alkanes are used as fuels

3.       The reaction is called Combustion 

4.       The word equation for  this chemical reaction is :

fuel (Hydrocarbon) + Oxygen → Carbon Dioxide + Water + ENERGY (heat, light, sound)

5.       If there is insufficient oxygen then the word equation is:

fuel (Hydrocarbon) + Oxygen → Carbon monoxide + Water + ENERGY (heat, light, sound)

6.       The problem with this reaction is that Carbon monoxide is produced this gas is a Poison to the human body (see objective 5.11)

7.       Where can you find incomplete combustion? In your Car

8.       What is used to reduce the harmful products from incomplete combustion? A Catalytic Converter

9.       During incomplete combustion a smoky flame is often seen, explain this observation This is unburnt carbon 

Extn: write a balanced equation (with state symbols) for the combustion of propane gas

C₃H_8(g)+5O_2(g)→3CO_2(g)+4H₂O_(l)

5.12 I can recall the problems associated with the fractional distillation of crude oil.

a. When crude oil undergoes fractional distillation there are too may long chain hydrocarbons (Eg. bitumen) produced and not enough short chain hydrocarbons (Eg. refinery gasses).

b. To solve these problems the long chain hydrocarbons undergo a chemical reaction called cracking (see objectives 5.13)

5.11 I can recall how nitrogen oxides are formed in car engines

a.       Write the general equation for the combustion of a fuel

Fuel + oxygen ---> Co2 + H2o + Energy

b.      During combustion the nitrogen in air can react to form what gases?

Nitric Oxide NO, Nitrogen Dioxide NO2, and NItrous Oxide N2O  

c.       What condition is necessary for this reaction to take place?

High Temperatures.

d.      In what common object is this condition found?

In cars.

e.      Why is this condition needed for nitrogen to react?

It is needed so that it could break the triple covalent bond because the molecule is inert.

f.        What are the dangers of the products from this reaction?

NItrous oxides create acid rain when mixed with with the water in the atmosphere and therefore creating acidic rain.

5.10 I can recall the problems associated with incomplete combustion

2.       What are the properties of carbon monoxide?

Colourless, odorless, poisonous

3.       Explain how carbon monoxide is formed

It is formed when there is a lack in oxygen in the respiration process.

Fuels + Insufficient oxygen à Carbon monoxide + Water + Energy

4.       Explain why carbon monoxide is poisonous

It is poisonous because it sticks to the hemoglobin and reduces the amount of oxygen going around the body.

5.9 I can describe the trend in boiling points and viscosity of the main fractions

a.       What is the trend in boiling point of the fractions?

The fractions at the higher end of the column have a lower temperature then the bottom end.

b.      Define viscosity (source your definition)

Viscosity is a fluids “thickness” or the fluency of the water.

c.       What is the trend in viscosity of the fractions?

The higher in the fractional column the liquid has a lower viscosity.

d.      What is the trend in colour of the fractions?

The fractions get lighter as they go up the column.

e.      Why is crude oil separated into fractions?
This is so that we would be able to use the hydrocarbons in the crude oil mixture.

f.        What process is used to separate crude oil into fractions?

Fractional distillation is used to separate the different hydrocarbons.

g.       What physical property allows this process to work?

            The different boiling points.