Well from my research I've calculated that pH + pOH = 14.00. in conclusion
pOH = 14.0 - 4.0 and so forth that equals 10.0 your welcome
Answer:
The concentration is 
Explanation:
From the question we are told that
The absorbance is 
The length is 
Generally absorbance is mathematically represented as

where
is the molar absorptivity of FeSCN2 with a value 
and
is the equilibrium concentration of FeSCN2
So

substituting values

