acids alkali bases Flashcards
UI
red - acid
green
purple - alkali
range of colours - quantitive
methyl orange
red - acid
orange
yellow - alkali
phenolphthalein
colourless - acid / neutral
pink - alkali
red litmus paper
blue in alkali
blue litmus paper
red in acid
acid definition
proton donor
releases H+ ions in water
ethanoic acid
CH3COOH
phosphoric acid
H3PO4
strong acid
fully ionise
higher concentration of H+
eg hydrochloric
weak acid
partially ionises
lower concentration of H+
eg ethanoic
base definition
proton acceptor
neutralises acids
alkali definition
soluble bases
substance which releases OH- ions when in water
common alkalis (4)
NaOH
KOH
Ca(OH)2
NH3
ionic equation for neutralisation
H+ + OH- > H2O
acid + metal
salt + hydrogen
effervescence + solid disappears
REDOX
acid + metal carbonate
salt + water + CO2
solid disappears + effervescence
NEUTRALISATION
acid + metal oxide
salt + water
solid disappears
NEUTRALISATION
acid + metal hydroxide
salt + water
solid disappears
NEUTRALISATION
acid + ammonia
ammoniUM salt
NEUTRALISATION
all acid reactions
make salts
exothermic
hydrogen test
lit splint
squeaky pop
don’t react K Li Na
too reactive + dangerous
don’t react Cu Ag Au
unreactive
less reactive than hydrogen
test HCl gas with blue litmus
DAMP to make HCl dissolve to make HCl (aq)
acid - red
hydrated salts
salts containing water of crystallisation
evaporate 2/3 of water
leave to cool/crystallise
filter + dry
anhydrous salt
heat to dryness
no water of crystallisation
anhydrous salt test for water
anhydrous copper sulphate + water
goes from white to blue
sodium solubility
soluble
potassium solubility
soluble
ammonium solubility
soluble
acids solubility
soluble
bases solubility
insoluble (hydroxides oxides + carbonates)
except sodium… potassium… ammonium… ammonia calcium hydroxide
nitrates solubility
soluble
chloride solubility
soluble
except silver and lead
sulphates solubility
soluble
except barium calcium + lead
making insoluble salts (5)
- precipitate
MIX 2 solutions STIR FILTER precipitate WASH - distilled water DRY - filter paper
why wash precipitate
distilled contains no other compounds that can react
to make it pure and remove solution
soluble salt methods (3)
acid + metal
acid + insoluble base
acid + soluble base (titration)
soluble salt - acid + metal/insoluble base
WARM acid add XS base/metal FILTER off xs to obtain filtrate HEAT filtrate to evaporate 2/3 of the water (saturated) COOL/CRYSTALLISE solution FILTER off water DRY between filter paper
why warm acid
speed up reaction
how to tell its in XS
solid stops disappearing(all acid reacts)
test for saturation
glass rod
crystals form in end
making anhydrous salt
once you have soluble salt solution heat to dryness not saturation
why use volumetric pippette
very acurate
why use burette
measure precisely
and add acid slowly / gradually
why run acid through burette
fills to end of tap
why swirl
mix round acid evenly
concentration
no. moles of solute in 1dm^3 of solvent
no. moles/volume
dm^3
cm^3/1000
soluble salt - acid + soluble base (alkali) 13
- add alkali to conical flask (VOLUMETRIC PIPETTE)
- add INDICATOR
- fill BURETTE with acid (record initial volume)
- let some acid out (fill the jet)
- add acid drop by drop + SWIRL
- till indicator changes colour
- record final volume and subtract initial to find amount of acid added
- repeat till CONCORDANT values
- AVERAGE concordant values and add average amount to alkali (no indicator)
- HEAT (evaporate 2/3 of water) till saturated
- COOL/CRYSTALLISE solution
- FILTER to obtain crystals
- DRY between filter paper
concordant results
two results within 0.1cm^3