Equilibrium 6 Flashcards
what is Ksp/ solubility poduct?
Ksp is the product of the concentrations of the ions of a sparignly soluble salt raised to the power equal to the no. of times the ion occurs in the eqn representing the dissociation of the salt, at a given temperature for a saturated solution.
what is ionic pdt
- applicable to all solutions as well as saturated solution
-it is the product of the concentrations of ions at any given temperature. - ionic pdt for a saturated soln is ksp/
what are the uses of Ksp (i)
it is used to calculate solubility of a sparingly soluble salt.
for AB salts
S²= Ksp
for AB2 salts
S . 2S. 2S= Ksp
4S³=Ksp
whata re the uses of Ksp (ii)
It is used to predict the precipitation of salt.
Solubility products is the upper limit of the ionic pdt of any sparingly soluble salt in saturated soluton.
if the ionic pdt exceeds Ksp, then ppt will occur
when calculating ionic pdt, when equal vlumes of reagents are taken, we should divide the molaritie by 2 since volume is doubled.
what are the uses of Ksp (iii)
checking the ppt of soluble alts or salting out
If hcl gas is passed through a saturated solution of the nacl, then the conc. of cl- ions will be increased. so the ionic pdt of nal
if we take a
saturated solution of sodium chloride and
pass HCl gas through it, then sodium chloride
is precipitated due to increased concentration
(activity) of chloride ion available from the
dissociation of HCl. As a eesult due to common ion effect the dissociation of nacl is suppressed, leading to the precipitation of nacl.
Sodium chloride thus
obtained is of very high purity and we can get
rid of impurities like sodium and magnesium
sulphates.
what is a buffer solution
The solutions which resist
change in pH on dilution or with the
addition of small amounts of acid or alkali
are called Buffer Solutions.
type of buffer solutions
(i) aolution of a single dubstance acts like a abuffer - ammonium acetate
(ii) solution of mixtures whcih act like a buffer
(a) acidic buffer= A mixture of acetic acid and
sodium acetate
(B) Basic buffer= a mixture of ammonium chloride
and ammonium hydroxide
how do buffer solutions work
They work on the basis of common ion effect.
Buffer solutions of known pH can be prepared from the
knowledge of pKa of the acid or pKb of base
and by controlling the ratio of the salt and acid
or salt and base.
importance of buffers
Many body fluids e.g., blood or urine have
definite pH and any deviation in their pH
indicates malfunctioning of the body. The
control of pH is also very important in many
chemical and biochemical processes. Many
medical and cosmetic formulations require
that these be kept and administered at a
particular pH.
The pH of the blood is maintained by 3 things:(pH=7.4)
- carbonate ion
-bicarbonate ion
-carbon dioxide
