Answer:
2FeBr3 + 3Na2S ➡️ Fe2S3 + 6NaBr
Explanation:
It is known that molarity is the number of moles present in a liter of solution.
Mathematically, Molarity = 
Hence, calculate the molarity of given solution as follows.
Molarity of citric acid = 
= 
= 0.173 M
As citric acid is a triprotic acid so, upon dissociation it gives three hydrogen ions.
Normality = Molarity × no. of hydrogen or hydroxide ions
= 0.173 × 3
= 0.519 N
Thus, we can conclude that molarity of given solution is 0.173 and its normality is 0.519 N.
Answer is A. The reason to create such is to conduct electricity, and metal conducts electricity.
Hope this helps, Tiara