Answer : The equilibrium concentration of in the trial solution is
Explanation :
First we have to calculate the initial moles of and
.
and,
The given balanced chemical reaction is,
Since 1 mole of reacts with 1 mole of
to give 1 mole of
The limiting reagent is,
So, the number of moles of = 0.0020 mmole
Now we have to calculate the concentration of .
Using Beer-Lambert's law :
where,
A = absorbance of solution
C = concentration of solution
l = path length
= molar absorptivity coefficient
and l are same for stock solution and dilute solution. So,
For trial solution:
The equilibrium concentration of is,
= 0.00050 M
Now calculate the .
Now calculate the concentration of .
Therefore, the equilibrium concentration of in the trial solution is