Advantages and disadvantages of methods of preparing alcohol

Industrial


Advantages -
It will be continuous
Reactions are reversible
Produces 100% yield
Fast reaction rate

Disadvantages -
Non Renewable
Requires a lot of energy
Requires high pressure and temperature

Fermentation

Advantages -
Gentle Temperature
Uses renewable sources (sugar cane)

Disadvantages -
A batch process - inefficient
Slow rate - Several days for each batch
Produces impure ethanol - needs further processing

3.8 I can describe the reaction between alkenes and bromine

1.       Write the word equation showing the reaction between ethene and bromine water
           Ethene + Bromine = 1,2-dibromoethane

2.       Draw the displayed formula of the reaction above

3.       Explain the observations
          Turns brown to colourless liquid
        

        


4.       Why does this reaction not need a catalyst?
          Because the C=C is reactive

5.       What type of reaction is this called?
          Addition Reaction

6.       Explain why this reaction is useful
          It's a chemical test that distinguish saturated and unsaturated hydrocarbons
          (alkanes and alkenes)

3.6 and 3.7 I can recall the general formula and displayed formulae of alkenes

4. What is the general formula for alkenes?

CnH2n

5. Describe and explain the trend in boiling point

Boiling point goes up as the chain gets longer because more intermolecular force is needed to break. 

6. Explain why there is no such compound as methene

Because Methane only has one carbon so it can't form a double bond.

7. How do you quickly identify from the displayed formula that the hydrocarbon is unsaturated?

Because there is double bond in the carbon so it is unsaturated.

3.5 I can recall the reaction of methane and bromine

1. Alkanes react with bromine in the presence of ultra violet light.

2. Explain why this condition is necessary.

The UV is the essential energy required in order for the chemical reaction to happen.  

3. What is this type of reaction called = Substitution Reaction.

4. State and explain the observations = Brown gas turns colourless because the bromine as a reactant is brown and the products bromomethane and hydrogen bromide is colourless

5. Draw the displayed formula of the reaction between methane and bromine (upload a photo)

6. Write out a balanced (with state symbols) the reaction between ethane and chlorine

C2H6 (g) + Cl2 (g) --> C2H5CL (g) + HCl (g)

7. State and explain the observations in this chemical reaction

Yellow Gas turns Colourless because the chlorine as a reactant is yellow and the products chloroethane
 and hydrogen chloride is colourless 

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

1. Saturated hydrocarbons are called alkanes

2. Small chain hydrocarbons 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 dangerous to the human body (see objective 5.11)

7. Where can you find incomplete combustion? Cars

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

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

    Grey Clouds of Gases & Nasty Smell

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

C3H8 + 5O2 --> 3CO2 + 4H2O

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

What is the General Formula for Alkanes:
C _nH_2n+2
Describe and explain the trend in boiling point:
The boiling point goes higher when there are more atoms in the molecule

THREE ISOMERS OF PENTANE:

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

Term	Definition	Example
Homologous series	Members of the same series, or family having similar chemical properties.	alkanes
Hydrocarbon	A hydrocarbon is a compound containing only hydrogen and carbon.	crude oil, methane, ethane, propane, butane, pentane
Saturated hydrocarbon	Molecules with a single bond throughout the whole structure	Any Alkanes (Methane)
Unsaturated hydrocarbon	Molecule with a double/triple bond	Any Alkenes (Ethene)
General formula	A mathematical formula to express the number of carbon and hydrogen atoms in a molecule	C nH2n+2
Isomerism	Molecules having the same formula, but are structured differently.	2,2 Dimethylpropane