Answer:
The equilibrium expression is:
CoC2O4(s)⇌Co2+(aq)+C2O2−4(aq)
For this reaction:
Ksp = [Co2+][C2O2−4]=1.96×10−8
Explanation:
Batteries will not clot if cobalt ions are removed from its cells. Some blood collection tubes contain salts of the oxalate ion,
C2O2−4
, for this purpose. At sufficiently high concentrations, the calcium
and oxalate ions form solid, CoC2O4·H2O (which also contains water bound in the solid). The concentration of Co2+ in a sample of blood serum is 2.2 × 10–3M. What concentration of
C2O2−4
ion must be established before CoC2O4·H2O begins to precipitate.
CoC2O4 does not appear in this expression because it is a solid. Water does not appear because it is the solvent.
Solid CoC2O4 does not begin to form until Q equals Ksp. Because we know Ksp and [Co2+], we can solve for the concentration of
C2O2−4
that is necessary to produce the first trace of solid:
I think it’s “Removed from”
Answer : The correct option is, (2) Energy is absorbed as bonds are broken.
Explanation :
As we know that the bonds are formed and breaks during the chemical reaction. Some energy is released or absorbed when the bonds are formed and breaks during the chemical reaction.
During the bond breaking, some energy is required to break the bonds.
During the bond formation, some energy is released to the formation of the bonds.
In the given reaction, the bond between the hydrogen-hydrogen in 
are breaking into two hydrogen. That means during the bond breaking, some energy is required or absorbed to break the bonds.
Hence, the correct option is, (2) Energy is absorbed as bonds are broken.
Answer:
Ea=5.5 Kcal/mole
Explanation:
Let rate constant are 
and 
at temperature 
and 
By using Arrhenius equation at two different two different temperature,
By putting value of R=2 cal/mole.K
By rounding off upto 2 significant figure;
It is +2 because it has a positive charge when the atom loses two electrons
