Question

I will participate in a practical course titled Synthesis of Coordination Compounds. One of the materials needed to synthesize sodium trioxalatoferrate (III) is sulphuric acid with the concentration of 6 N (normality). Can someone explain the possible reasons the producers of H_2SO_4 with said concentration use normality instead of molarity for the unit of concentration? Can someone enlighten me on why equivalent concentration is sometimes used over molarity in lab products?

Answer 1

Normality is used over molarity in certain chemical processes, such as titrations and redox reactions, where the number of equivalents in a reaction is important. It is particularly useful for acids like sulphuric acid that can release more than one proton, hence making normality an effective measure for its neutralizing capacity.

Step-by-step explanation:

In chemistry, normality is a measure of concentration that is equivalent to the molarity of a solute per liter of solution, specifically for reactions involving acids and bases. Normality is especially useful in scenarios such as titrations, where it is important to know the number of equivalent weights of a reactant. For example, sulphuric acid (H2SO4) is diprotic, meaning it can donate two protons (H+) per molecule, so a 6 N solution can react with twice the amount of base that a 6 M solution of a monoprotic acid could.

In the context of the industrial synthesis of sulfuric acid and analytical methods such as redox reactions, where equivalent concentration matters, normality is often the preferred unit of concentration. For instance, in the titration of sulphuric acid against sodium hydroxide, the normality would directly indicate the acid's capacity to neutralize the base. Moreover, in redox titrations, the normality can clarify the number of equivalents of an oxidizing or reducing agent that a substance can supply or consume, further emphasizing its practicality in certain applications over molarity.