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