science exam prep Flashcards
define crude oil
a mixture of hydrocarbons
define a hydrocarbon
a molecule/compound containing hydrogen and carbon ONLY
define an alkane
a hydrocarbon containing only SINGLE bonds
what is the general formula for an alkane
CnH2n+2
define and alkene
a hydrocarbon containing at least one DOUBLE bond
what is the general formula for an alkene
CnH2n
what is fractional distillation?
a method of separating hydrocarbons based on their boiling points
what is bromine water and what is the difference when you add alkene and all alkanes to it?
- bromine water is a chemical hat is orange/brown
- if you add alkanes, the water does NOT change colour, it stays orange/brown
- if you add alkanes, the water will change colourless
what is cracking?
it breaks long chain hydrocarbons into more useful short chain hydrocarbons
what is a catalyst?
a chemical that speeds up a reaction
what are the first 4 alkanes?
1- methane
2- ethane
3- propane
4- beutane
finish the equation:
metal + acid = ?
metal + acid = hydrogen + water
what is portable water?
water that is safe to drink
which gas makes up 78% of the atmosphere?
nitrogen
finish the equation:
acid + alkali —> ?
acid + alkali —> salt + water
why is cracking important?
it is breaking down large hydrocarbons into more useful short chain hydrocarbons
what is the method for separation crude oil called?
fractional distillation
when testing gases, what happens to oxygen?
glowing splint re-lights
when testing gases, what happens to carbon dioxide?
turns lime water cloudy
when testing gases what happens to hydrogen?
the lit splint gives a squeaky pop
when testing gases, what happens to chlorine?
damp litmus paper turns white
