c9 & c5 mocks revision
what is a hydrocarbon
a compound containing only hydrogen and carbon
what is crude oil
a complex mixture of hydrocarbons
what is the formula for an alkane
CnH2n+2
why are alkanes 'saturated' hydrocarbons
because their carbon atoms are joined by a single bond
list the reactivity series of metals
Potassium, Sodium, Calcium, Magnesium, Aluminium, Carbon, Zinc, Iron, Tin, Lead, Hydrogen, Copper, Silver, Gold
what happens when a metal reacts with other substances
the metal atoms lose electrons and form positive ions
what happens when a metal reacts with water
a metal hydroxide and hydrogen are formed
what happens when a metal reacts with a dilute acid
a salt and hydrogen are formed
how do displacement reactions work
the more reactive element displaces the less reactive element from its compound
what is crude oil a mixture of
hydrocarbons
what comes out the top of a fractionating column
small molecules such ad gasoline for cars and refinery gases
what comes out the bottom of a fractionating column
large molecules such as fuel for ships and bitumen for roofs and roads
properties of small molecules
high viscosity
low boiling points
high flammability
properties of large molecules
low viscosity
high boiling points
low flammability
what are the products of complete combustion of hydrocarbons
carbon dioxide and water
what is needed for complete combuston of hydrocarbon
a good oxygen supply
why is a good oxygen supply crucial for complete combustion of hydrocarbons
it fully oxidises the hydrogen to water and the carbon to carbon dioxide
what are the products of incomplete combustion of hydrocarbons
water, carbon monoxide and/or soot
why does incomplete combustion of hydrocarbons occur
when there isnt enough oxygen to oxidise the carbon fully
why is carbon monoxide dangerous
it binds to haemaglobin in red blood cells, stopping them carrying oxygen around the body
how can a soluble salt be made
by reacting an acid with a metal or carbonate
what is produced when acid is reacted with a metal
salt + hydrogen
what is produced when an acid is reacted with a carbonate
salt + water + carbon dioxide
How do you make salts from an insluble base (4points)
1. add the insoluble reactant (in powder form) to a beaker of the acid, until there is unreacted powder
2. filter the mixture into a beaker, then it will only contain salt and water
3. heat the solution in an evaporating basin over a water bath until crystals start to form
4. take it off the hat and wait a day so larger crystals can form