Topic 4 Flashcards
salt prep and solubility, acids bases and indicators, extracting metals, reactivity series, gas and ion testing
What are the 5 general salt types (not products)
- acid + metal carbonate
- acid + metal hydrogen carbonate
- acid + metal hydroxide
- acid + metal oxide
- acid + metal
Acid + metal carbonate ->
salt + water + carbon dioxide
Acid + metal hydrogen carbonate ->
salt + water + carbon dioxide
acid + metal hydroxide ->
salt + water
acid + metal oxide ->
salt + water
acid + metal ->
salt + hydrogen
soluble acid + soluble base ->
soluble salt + water
salt prep : soluble acid + soluble base
- neuturalisation by titration
- evaporation
- drying
soluble acid + insoluble base ->
soluble salt + water
salt prep 2 : soluble acid + insoluble base
- neuturalisation
- filtration
- evaporation
soluble salt + soluble salt ->
insoluble salt + soluble salt
salt prep 3 : soluble salt + soluble salt
- precipitation
- filtration
- washing then drying
solubility rules (5)
No3- : all nitrates soluble
Cl- : all chlorides soluble except agcl, pbcl2
so4 2- : all sulfates soluble except caso4 pbso4 baso4
OH: all hydroxides insoluble except g1 and g2 slightly soluble
CO3 2- : all carbonates insoluble except g1 and (NH4)2CO3
what is water of crystallisation
crystalline salt which is hydrates or chemically combined with water
what does anhydrous mean
complete dryness
acidc and amphoteric oxide test
reacts with metal carbonates (base) to form co2 gas
acidic oxide test
dissolves in water and lowers ph (test with universal indicator)
basic + amphoteric oxide test
rects with acides and is neuturalised
ph of non metal oxides and examples
most acidic
so2 so3 co2
ph of metal oxides and examples
most are basic eg caO and na2o
what is a amphiprotic oxide and example
can donate and accept protons
eg water
H20 turns into h30 + or OH-
what is an amphoteric oxide and example
reacts like and acid and base eg aluminium hydroxide
How is quick lime formed (cao) and equation
by the decomposition of CaCO3
- caco3 (s) -> CaO (s) + CO2 (g)
how is slaked lime formed and equation
by the addition of water to quick lime
CaO (s) + H2O (l) -> Ca(OH)2 (s)
how is limewater formed
more water added to slaked lime
how is lime stone formed and equation
by bubbling CO2
examples of metals that react vigorously with water
potassium, sodium, calcium
products when metals react with water
metal hydroxide and H2 gas
calcium reaction with water. UI result
bubbles of gas are given off after a few secounds. when tested with universal indicator water is now alkali
sodium reaction with water.
melts and skims over the surface, producing a stream of small bubbles. sometimes a yellow-orange flame appears
potassium reaction with water
immediatly produces a lilac flame as it skims around the surface making a fizzing noise
magnseium reaction with steam
reacts vigorously
reactivity series
- potassium
- sodium
- calcium
- magnesium
- aluminium
- zinc
- iron
- lead
- copper
- silver
- gold
what happens in dispacement reactions
the meta in a compound is replaced by the more reactive metal to form a new compound
extraction methods
- found pure
- by reduction using carbon, coke or charcoal
- electrolysis
metals found pure
silver and gold
metals extracted by reduction
copper lead iron zinc
metals extracted by electrolysis
alumninium magnesium calsium sodium potassium
most common aluminium ore
bauxite
how is alunminium etracted
electrolysis of molten bauxite, cryolite is mixed in to help it melt easier
overall aluminium extraction reaction
2Al2O3 (l) -> 4Al (l) + 3O2 (g)
what is insterted into the molten mnixture during aluminiujm extraction
graphite electrodes
what happens at the negative cathode
positive al ions drift to the cathode, they gain electrons and become aluminium atoms
what happens at the positive cathode
negative oxide ions drift to the positive anode they lose electrons and become oxygen molecules
where is iron extracted
in a blast furnace
what is the iron ore
haematite
main iron extraction equation
Fe2o3 (s) + 3CO (g) -> 2Fe (l) + 3CO2 (g)
first step in iron extraction
coke reacts with oxygen in the hot air to make carbon dioxide
when Co2 reacts with more hot coke what does it form
carbon monoxide
what is reducing the iron oxide
carbon monoxide
how is impurities removed in the extraction of iron
limestone thermally decomposes and the product further reacts with the impurites to form slag CaSiO3
