Tuesday, June 21, 2011

3.8 Describe the addition reaction of alkenes with bromine, including decolourising of bromine water as a test for alkenes

Create blog post titled '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 water -----> bromoethane + hydrogenbromide
2.       Draw the displayed formula of the reaction above
Take a photo of the answers to 1. and 2. and upload to your blog
3.       Explain the observations: 
4.       Why does this reaction not need a catalyst? Because alkenes are highly reactive.
5.       What type of reaction is this called? Addition reaction
6.       Explain why this reaction is useful: 

3.5 Recall the reaction of methane with bromine to form bromomethane in the presence UV light

Alkanes react with bromine in the presence of: UV Light. 
Explain why this condition is necessary: the UV light is the source of energy needed to break the weak inter molecular forces in between molecules.
  What is this type of reaction called: substitution reaction 
 State and explain the observations: Alkanes are colourless and bromine is brownish orange, when the reactants are given energy to break inter molecular bonds the bromine is less saturated and the product therefor turns colourless 
Write out a balanced (with state symbols) the reaction between ethane and chlorine: C2H+ Clà C2H5 + HCl
 State and explain the observations in this chemical reaction: The chlorine starts as a green/yellow gas. When it reacts the chlorine is less saturated and the product is more saturated making the product colourless





Tuesday, May 24, 2011

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 -----> energy + oxides
b.      During combustion the nitrogen in air can react to form what gases? NOx gases
c.       What condition is necessary for the formation of these gases? High temperature
d.      In what common object is this condition found? Cars
e.      Why is this condition needed for nitrogen to react? Nitrogen molecules are diatomic and have triple covalent bonds 
f.        What are the dangers of the products from this reaction? Cancer, Lung disease, 

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





Term
Definition
Example
Homologous series
Organic compounds with a similar general formula

 Alkane
Hydrocarbon
 A compound of hydrogen and carbon

 Alkene, alkanes
Saturated hydrocarbon
 A hydrocarbon formed with simple bonds

 Alkanes
Unsaturated hydrocarbon
A hydrocarbon with one double or triple bond

 Alkenes
General formula
 A formula to show the mathematical relations between a carbon and hydrogen

 CnH2n+2
Isomerism
Compounds with the same molecular formula but different structural formulas 

 2,2 Dimethylpropane  

Tuesday, May 17, 2011

petroleum gas

fuel oil

kerosine

diesel

petrol

bitumen

5.8 I can recall the names and uses of the main fractions obtained from crude oil

5.10 I can recall the problems associated with incomplete combustion

What are the properties of carbon monoxide.. 
Made up of 1 carbon atom and 1 oxygen atom.
Flammable
colourless, odorless and tasteless gas
Explain how carbon monoxide is formed.. When there isn't enough oxygen to produce carbon dioxide
Explain why carbon monoxide is poisonous.. It bonds with the hemoglobin in the red blood cells which reduces their capacity to carry oxygen around the body

5.10 I can recall the problems associated with incomplete combustion

What are the properties of carbon monoxide.. 
Made up of 1 carbon atom and 1 oxygen atom.
Flammable
colourless, odorless and tasteless gas
Explain how carbon monoxide is formed.. When there isn't enough oxygen to produce carbon dioxide
Explain why carbon monoxide is poisonous.. It bonds with the hemoglobin in the red blood cells which reduces their capacity to carry oxygen around the body

Tuesday, May 10, 2011

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

a.     What is the trend in boiling point of the fractions? As you get lower in the fractions, the higher boiling point     
b.     Define viscosity Thickness of liquid


      c.     What is the trend in viscosity of the fractions? Higher viscosity, higher melting point
     d.    What is the trend in colour of the fractions? Higher viscosity, darker the colour
     e.    Why is crude oil separated into fractions? Crude oil on its own is useless, but the fractions are useful
     f.     What process is used to separate crude oil into fractions? Fractional distillation
     g.    What physical property allows this process to work? The boiling points 

5.6 I can recall what crude oil is made from.

2.       Read pg 139 (down to word plastics) Chem 4 You
a. Define the word hydrocarbon…
Organic compounds which contain only carbon and hydrogen. and carbon
b. What is crude oil made from?
There are 2 elements that make up crude oil - hydrogen and carbon.
c. Define the word compound…
When 2 or more different elements are bonded together.
d. Define the word mixture….
When 2 or more compounds or elements aren’t chemically bonded together.

4.       Read pgs 140 & 141 Chem 4 You and add these to the table above
d. How long does crude oil take to make?
About 150,000,000 years.
e. Where does the energy in crude oil originally come from?
The sun.
f. How is crude oil different from coal?
Crude oil derived from plants and animals from the sea. It is a hydrocarbon.
Oil derived from trees that were under swamps and crude oil is not a hydrocarbon.
g. Crude oil, coal and natural gas are collectively known as _________ fuels
fossil 
h. How is crude oil transported when it is extracted from the ground?
Either by pipeline or with oil tankers which transports the oil around the world.