Producing alcohol by Fermentation and in Industry

FERMENTATION
Advantages

• Raw material is renewable
• Fermentation takes up little energy
• It can transform food into a more stable form

Disadvantages:

• Does not produce as much energy.
• Very time consuming
• Lots of workers are used to help the process.

IN INDUSTRY

Advantages:

• Much faster than fermentation
• One stage process

Disadvantages:

• Non renewable
• Could potentially be dangerous

Alkanes

METHANE

ETHANE

PROPANE

BUTANE

PENTANE

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

   Saturated hydrocarbons are called alkanes

·         Small chain alkanes are used as fuels

3.       The reaction is called combustion

4.       The word equation for  this chemical reaction is :

fuel (methane) + oxygen → carbon dioxide + water + ENERGY (heat, light, sound)

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

fuel (methane) + oxygen → carbon monoxide + water + ENERGY (heat, light, sound)

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

7.       Where can you find incomplete combustion? In cars

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

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

10.   Describe the two chemical tests for water   blue anhydrous cobalt chloride turns pink

11.   Describe the chemical test for carbon dioxide gas lime water turns milky

12.   Describe a physical test for water- boiling point 100 Celsius

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

3.1 I can explain the terms homologous series, hydrocarbon, saturated, unsaturated, general formula and isomerism

Term	Definition	Example
Homologous series	A family of compounds with the same general formula	alkanes
Hydrocarbon	a compound containing hydrogen and carbon	Methane
Saturated hydrocarbon	the fact that each carbon has maximum number of bonds	ethane, propane
Unsaturated hydrocarbon	hydrocarbons which have double or triple covalent bonds.	butane
General formula	A mathematical formula to show how many carbons and hydrogens there are in the homologous series.	CnH2n+2
Isomerism

5.13 I can describe catalytic cracking of long chain hydrocarbons

1.How are long chain hydrocarbons broken down?
By using heat.


2. What is the main safety aspect of the experiment? 
As the experiment goes on, you should not allow the water to go back to the test tube, as it will hit the steam and may cause an explosion.


3. What is cracking?
When long chain hydrocarbons are broken down, into smaller chains by using heat.. 


4. Why does the rate of gas production increase as the experiment goes on?
Because when the hydrocarbons get heated, the experiment moves faster.


5. Why does the ceramic pot turn black?
Because of interaction with organic material


6. What is the ceramic pot used for?
They are used as a catalyst to speed up the experiment


7. Why is the gas collected over water?
Because the gas is less dense than air, so then it goes into the test tube.


8. Why is cracking useful?
Because short chain hydrocarbons are more useful than long chain hydrocarbons.

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

a. When crude oil undergoes Fractional Distillation there are too many large chain hydrocarbons e.g. (bitumen) produced and not enough small chain hydrocarbons e.g. petrol 


b. To solve these problems large chain hydrocarbons undergo a chemical reaction called Cracking..

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 ------> carbon dioxide +water+energy 

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

nitrogen monoxide, nitrogen dioxide

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

high temperatures

d.      In what common object is this condition found?

Cars

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

Because nitrogen has a very strong covalent bond.

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

When the products dissolve into water, they produce nitric acid which contributes to acid rain, which then erodes limestone buildings.