ACIDS & BASES Flashcards
arrhenius theory
in aq,
acid = gives H+
base = gives OH-
not all acids are soluble in water
bbl theory
acid = proton donor
base = proton acceptor
HCl + H2O ⇌ H3O+ + Cl- [H+ donated]
NH3 + H2O ⇌ NH4+ + OH- [H+ accepted]
limited to protonic solvents
can’t explain acid-base reactions that dont involve proton transfer
lewis theory
acid = electron pair acceptor
base = electron pair donor
properties de acids y bases
pH < 7
sour
pH > 7
soap/slippery
bitter
strong acid vs weak acid
complete dissociation vs partial dissociation
HCl → H+ + Cl-
CH3COOH → H+ + CH3COO-
if in water, H+ will react with water to form hydronium ion H3O+
litmus paper
acid = blue litmus → red
base = red litmus → blue
bromthymol blue
blue base
yellow acid
green neutral
methyl orange
acid = red
base = neutral = yellow
test for hydrogen
lighted splint burns with a pop
test for oxygen
glowing splint relights
test for ammonia
damp red turns blue
test for chlorine
damp blue turns red then bleaches white
test for co2
in CaOH turns milky white due to presence of insoluble white CaCO3 precipitate
caoh = lime water
use of NH4NO3
fertilizers
use of KNO3
gunpowder
use of MgSO4
medicine
use of CaCO3
marble, marine animal shell, statues, limestone
Na2CO3?
washing soda
NaHCO3
baking soda
what is oxide
compounds made from one or more atoms of oxygen combined with one other element
give example of amphoteric oxide
Al2O3 forms complex aluminate salts with bases and simple salts with acids
types of oxides
- metal oxides (basic)
- non-metal oxides (acidic)
- amphoteric (these show both acidic and basic propeties)
- neutral (these show neither acidic nor basic properties)
how to form a soluble salt
- acid-base titration
- acid + excess reactive metal (not very reactive metal because reaction is very violent)
* use excess so that all acid reacts and the salt does not have any acid in it. - acid + excess metal carbonate/bicarbonate
acid base titration
put acid in beaker, use phenolphthalein as indicator first time and stop when it becomes slightly pink which shows the solution is neutral then repeat without indicator
how to form insoluble salt
(1) direct combination (just put them together and heat)
- Fe+S=FeS
(2) precipitation method
* NaI+AgNO3 = AgI + NaNO3
SNAP are soluble (sodium, nitrate, ammonium, potassium)
so the precipitate has to be AgI
acid rain
- volcanic eruptions, burning of fossil fuels release sulphur and nitrogen oxides.
- in car engine enough energy for N and O to fuse and form NO.
- when released through exhaust in atmosphere, if thunder strikes perfectly, the NO released bonds with another O to form NO2.
- when rain happens SO2 and NO2 reacts with water to form nitric and sulfurous, sulfuric acid
normal rain = slightly acidic because of presence of co2
catalytic converter
- attached to exhaust, reduces NO to N2, which is not a pollutant
- however causes increased exhaust noise and sometimes engine performance issues.
hydrodesulfurization
(of crude oil) sulphur content is removed so that upon fractional distillation, it’s components also don’t have sulphur hence reducing carbon emissions immensly
pros of hydrodesulfurization
- lower sulfur levels minimize corrosive effects on pipeline
- lowers maintenance costs for vehicles
cons of hydrodesulfurization
- high pressure and temp required
- high operational costs
- produces hydrogen sulfide (H₂S) which is a toxic and corrosive gas
processes that extract hydrogen from gases like methane release a lot of carbon emissions
acid+metal
salt+hydrogen gas
single displacement reaction, na+hcl→nacl+h2
acid+base
salt+water
metal oxides and hydroxides are basic in nature
double displacement reaction, koh+h2so4→k2so4+h2o
metal carbonates/bicarbonates+acid
salt+co2+h2o
carbonates are salts of carbonic acid and are weak bases
caco3+hcl→cl2co3+co2+h2o
