Acids Flashcards
acid
hydrogen containing solution that releases hydrogen ions, gives protons
hydrogen ion
single proton
whats A(-)
anion
example of acid
HA —- H(+) + A(-)
acid reaction with water
HA + H20 —- H30(+) + A(-)
hydronium cation
H30(+)
why does hydronium cation form
hydrogen ion attracted to water molecule
strong acid
fully ionized in water (full reacts with water producing high concentration of hydronium ions, ionic components move left to right), low pH
types of strong acid
nitric (HNO3), sulfuric acid (H2SO4), hydrochloric acid (HCl)
weak acid
partially ionised in water (incompletely reacts with water producing few hydronium ions), dissociation is reversible
types of weak acid
organic acid, CH3COOH, CH3 is proton, COO is anion
carbonic acid
H2CO3
what happens when co2 dissolves in water
exists in acidic equilibrium
what happens at equilibrium
water contains co2/carbonic acid/bicarbonate ions/carbonate/hydrogen ions (form hydronium ions and make acid)
what acidifies ocean
when more hydrogen ions are released
whats a base
compound that produces hydroxide ions,
accepts protons, neutralises acids
whats the cation
Na+
example with water
NaOH + H20 — Na (+) + OH(-)
strong base
dissociate 100% with water, produces hydroxide cations
strong base types
potassium hydroxide, KOH
weak base
indirectly makes free OH ions from water
what happens if an element gains hydrogen ions
its a weak base
limestone
when water/co2 contact calcium carbonate in limestone it accepts protons forming calcium hydrogen carbonate
what does carbonate become
weak base
does strong mean concentrated
no
does weak mean diluted
no
whats pH
measure of hydronium ions, log scale
hydronium ions conc
1.0 x 10 (-7) mol/dm(3)
work out hydronium conc to pH scale
-log (1x10(-7)), log on calculator
how to work out with acid conc
same thing
how to work out how many hydronium in pH number
example of pH 7.40
change to -7.40 then press shift on log to get inverse log = 10 (-7.40)
equilibrium
forward/reverse reactions are equal
equilibrium constant
conc of products/conc of reactants
large k value (larger than 1000) …
favours products
intermediate k value (0.001-1000)
both are equal
small k value (less than 0.001)
favours reactants
ka equation
ka= (H30 x conc of products)/conc of reactants
Pka equation
PKa = -log(ka)
calculate kw
multiply conc of hydrogen ions and hydroxide ions
at 25C H+ and OH- are…
neutral, 1x10(-7)
what is kw at 25C
1 x 10 (-14)
Pkw at 25C is…
14