Seperate Chemsitry 2 Flashcards
How do you carry out a flame test to test for Lithium ions?
Fist clean a microme wire by dipping it into hydrochloric acid and rinse with distilled water
Dip the wire loop into a sample of the metal compound at out on a blue flame and record the flame color.It should turn to a red flame
How do you test for a precipitate?
Add few drops of sodium hydroxide solution to a solution of your compound you want to test.If a hydroxide precipitate forms you can use its color to tell which metal ion was in the compound.
How do you test for ammonia gas?
Hold damp red litmus paper over your gas and to see if ammonia gas the litmus turns blue
How do you test for a halide ion?
Test for halide add some dilute nitric acid followed by a few drops of silver nitrate solution
Chlorine gives white precipitate
Bromine gives cream precipitate
Iodine gives yellow predicate
How do you test for carbonates?
Add some dilute acid to solution the mixture will fizz
Hw do you test for gas to be carbon dioxide?
By bubbling carbon dioxide through limewater and should turn limewater cloudy.
How do you test for sulfate ions?
Add some dilute hydrochloride acid to sample then add some barium chloride solution.
If sulfate ion present white precipitate of barium sulfate forms
What is flame photometry?
Why is flame photometry used?
Is an instrumental method that allows you to identify ions in a dilut solution
To identify different ions in a mixture
Advantages of using machines to analyze unknown substances?
Sensitive and fast and accurate
What is the homologous series?
What are alkanes homologous series for?
Group of chemicals that have similar chemical structures
Alkanes are a homologous series of hydrocarbons they just contain one carbon atom and one hydrogen atom
What is the general formula of the alkenes?
CnH2n
What are Alkenes homologous series of?
Hydrocarbons with a carbon double bond C=C
Why are Alkenes unsaturated?
Because they can make more bonds as the double bond can open up allowing two carbon atoms to bond with another atom
How do you test for Alkene?
By using bromine water.When shaken together,an alkene will decolourise bromine water,turning it from orange to color less.
Hydrocarbons are oxidized in what type of reaction?
Combustion
Neutralization
Displacement
Combustion reactions
What are polymers?
What is monomer?
Substances of high average relative molecular mass made by joining up monomers
Lots of small repeating units that make up addition polymers.
What are the properties of Poly(ethene) and poly(propene)?
Poly(ethene):
Properties-flexible,cheap and insulator
Uses-plastic bags and bottles
Poly(propene):
Properties-flexible,strong and tough
Uses-furniture and ropes
how are polyesters formed?
When dicarboxyclic acid monomers and diol monomers react together
How is ester link formed?
When carboxyclic group reacts with the alcohol group
Why are polyesters condensation polymers?
Each time an ester link forms water is lost
What is the structure of DNA,starch and protein polymers?
DNA:complex molecule that contains genetic information
contains two strands each strand is made up of nucleotide monomers that bond together in polymerisation reaction
Made up from 4 different monomers called neucolitides
Protein:
Polymers made from monomers called amino acids
Starch:
Large complex carbohydrates made up of smaller unites of carbohydrates
cons of disposal of polymers in landfill sites and by combustion?
Landfills:
Lots of valuable land is quickly getting used up for these landfill sites
Polymers are non biodegradable as they don’t break down
Combustion:
Produces lots of energy and CO2 so global warming
Toxic gas released
Pros and cons of recycling polymers?
Pros:reduces emission of greenhouse gases
Uses less water and energy resources
Cons:harmful to plants and animals
They need to be separated before recycling so expensive
