separate chemistry II Flashcards
why must ever test for an ion be unique?
because you won’t know which specific ion it is if more than one gave the same result
flame test for these ions in solids:
- lithium
- sodium
- potassium
- calcium
- copper
- lithium: red
- sodium: yellow
- potassium: lilac
- calcium: orange/red
- copper: blue/green
test for these ions in a sodium hydroxide solution:
- aluminium
- calcium
- copper
- iron (II)
- iron (III)
- ammonium
- aluminium: white precipitate
- calcium: white precipitate
- copper: blue precipitate
- iron (II): green precipitate
- iron (III): brown precipitate
- ammonium: pungent smelling gas produced and this gas turns damp red litmus paper blue
chemical test for ammonia
turns damp red litmus paper blue, also forms a white smoke of ammonium chloride when hydrogen chloride gas is held near it
why are alkanes saturated hydrocarbons?
they don’t have a double bond and the compounds are only made up of hydrogen and carbon
what is the general formula for alkenes?
CnH2n
what is the general formula for alkanes?
CnH2n+2
what does the 1 in but-1-ene tell you?
tells you where to place the double bond
why can methane not be an alkene?
because it only has one bond and you need 2 to make a double bond
how can you use bromine water to distinguish between alkanes and alkenes?
alkenes react with bromine water as they change from orange to colourless, alkanes do not react with bromine water
what forms when an alkene/alkane react with oxygen?
alkane/alkene + oxygen –> carbon dioxide + water
what are the properties and uses of poly(ethene) and poly(propene)?
poly(ethene):
- properties= flexible, cheap, electrical insulator
- uses= plastic bags and bottles, coating of electrical wires
poly(propene):
- properties= flexible, strong
- uses= buckets, crates
what are the advantages and disadvantages of recycling polymers?
advantages:
- reuse waste materials
- saves crude oil as it is finite
- saves money
disadvantages:
- difficult and expensive to separate the polymers
what is dna (inc polymer)
dna is a polymer made from 4 different monomers called nucleotides
what is starch a polymer based on?
what is protein a polymer based on?
starch is a polymer based on sugars
proteins are polymers based on amino acids
