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


Answer: It's D
Explanation:
I just did this question and i picked C but it's actually D
1. research question
2. background research
3. hypothesis
4. <span>Controlled experiment
5. data analysis
6. data collection
7. conclusion</span>