Advantages and disadvantages of the 2 methods for preparing alcohol.

Fermentation 


Advantages:

• Raw material used is fermentation is renewable
• Conditions needed is warm, normal pressure
• Little energy is needed

Disadvantages: 

• Alot of workers are needed
• Slow process

Industrialisation

Advantages

• Few workers needed
• Reaction is faster (fast process)
• Purity of the product is pure

Disadvantages

• A lot of energy is needed
• High temperature and pressure is needed
• Raw materials used is non-renewable

Yr 10 chemistry EOY exa

• Read the question CAREFULLY (e.g. - state the SYMBOL)
• What charge on ions formed ? DON'T say NEGATIVE CHARGE ION, WRITE -1
• Effervescence is the same as FIZZES on surface when Sodium is placed in water. Why the UI is  alkali when sodium is added to water - because solution formed is a alkali (sodium hydroxide)
• State the colour the flame becomes Yellow/orange when a piece of platinum wire is dipped into a solution in a trough then held in a roaring bunsen flame. 
• Relative mass for electron is 1/2000 NOT NOT NOT NOT NOT NOT ZERO 0 
• Outline how a sample of pure propanone can be obtained from mixture : 1) Proponane boils before water 2)Heat 3) stop collecting condensate after 56c

'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 is higher up the homogeneous series because more energy is needed to break the strong covalent bonds.

6.       Explain why there is no such compound as methene

There is only one carbon atom and no other carbon atom to share a double bond with.

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

By looking at the structure there should be at least one carbon carbon double bond.

"3.5 I can recall the reaction of methane and bromine"

 1.   Alkanes react with bromine in the presence of UV light.

 2.    Explain why this condition is necessary?
        UV light provides the energy  needed to break the Bromine bonds. 

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

4.       State and explain the observations : Brown/Orange (Bromine) and the product (Bromomethane + Hydrogen Bromide) will turn 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 (chlorine) turns to a colourless (products are colourless)

--> Bromomethane

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

1.       Saturated hydrocarbons are called Alkane

2.       Small chain Alkanes are used as fuels

3.       The reaction is called combustion

4.       The word equation for  this chemical reaction is :

fuel (alkane) + Oxygen→ Water + Carbon dioxide + ENERGY (heat, light, sound)

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

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

6.       The problem with this reaction is that carbon monoxide is produced this gas is a threat 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? catalytic converter (converts carbon  monoxide --> Carbon dioxide)

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

The smoke is the unburnt carbon in the incomplete combustion  which forms soot.

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

C3H8(g) + 5O2(g) → 3CO2(g) + 4H2O(l)

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

3. CnH2+2
4. The more atoms in molecules, the higher the boiling point.

5.    Draw the displayed formula of the three isomers of pentane

Pentane, Butane, Propane, Ethane , Methane

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, alkenes
Hydrocarbon	A hydrocarbon is a compound containing only hydrogen and carbon.	crude oil, methane, ethane, propane, butane, pentane
Saturated hydrocarbon	Molecules with a  carbon carbon single bond throughout the whole structure	e.g. of Alkanes (Methane)
Unsaturated hydrocarbon	Molecule with a carbon carbon double/triple bond	e.g. of Alkenes (Ethene)
General formula	A mathematical formula to express the number of carbon and hydrogen atoms in a molecule	CnH2n+2 , CnH2n
Isomerism	Molecules having the same formula, but are structured differently.	2,2 Dimethylpropane