Preparation of (250 mL of 0.1M) Standard Solution of Oxalic Acid

Objective

Preparation of (250 mL of 0.1M) standard solution of oxalic acid.

 

Theory

A standard of oxalic acid refers to a precisely known high-purity substance that can be dissolved in a specific volume of solvent to create a primary standard solution. To prepare a designated quantity, a known weight of the solvent is dissolved, typically using a primary standard substance. 

The chemical formula for oxalic acid is (C2H2O4), and its most prevalent form is the crystalline hydrate (COOH)2H2O. First synthesized in 1776, oxalic acid has been recognized as a component of wood sorrel since the 17th century. It can be produced through various methods, such as heating sodium formate with an alkali catalyst, oxidizing carbohydrates with nitric acid, heating sawdust with caustic alkalis, or fermenting sugar solutions with specific molds. 

Oxalic acid, or ethane dioic acid, belongs to the carboxylic acid family and appears as a colorless, crystalline, poisonous chemical compound. The common form of oxalic acid is wood bleach. It'sIts typical applications include serving as an acid rinse in laundries to remove rust and ink stains and being a primary ingredient in commercial formulations for scale removal from vehicle radiators. Potassium permanganate is a primary standard substance for standardizing the solution of oxalic acid. 

In chemistry, stoichiometry has been utilized to quantify atoms, molecules, and ions by measuring the mass of pure substances and calculating the number of chemical entities using molar masses (moles). Additionally, the concept of molarity has been crucial in representing solution concentration. Molarity is calculated in moles per liter (mol/L) of a solution, which is determined by the gram molecular weight of the solute. 

Moles solute / vol solution=n(moles))/V(L)) =M(mol/L) 

In the case of preparing a 0.1M solution of Oxalic acid in 250mL, the hydrated oxalic acid, represented as C2H2O4.2H2O, has a molecular mass of 126. To prepare an M/10 oxalic acid solution, 12.6 g of oxalic acid per literlitre should be dissolved. 

Consequently, 3.15 g of oxalic acid crystals should be dissolved in water to yield 250 mL of the solution. 

 

Oxalic acid Uses

  • Industrial Uses - It is used in industries for mineral processing, sterilizing equipment, and bleaching clothes in the textile sector. 
  • Cleaning Agent- It is used as a bleaching agent for wood and for the removal of rust and ink stains.  
  • Reducing Agent - It is used as a reducing agent in chemical reactions.  
  • Chelating Agent - It is used in industrial processes like textile dyeing and metal cleaning as a chelating agent due to its ability to form stable metal ion complexes. 

 

Learning Outcomes

Students understand 

  • The concept of oxalic acid. 
  • The uses of oxalic acid.
  • The technique of handling the apparatus and how to prepare a solution.