Preparation and Standardization of Oxalic Acid (0.1m)

Oxalic Acid (0.1M) 

Molecular formula: H₂C₂O₄ ⋅ 2H₂O = 126 

Molecular weight: 90.03 

Preparation: Dissolve 6.3 g of oxalic acid in sufficient water to produce 1000 mL. 

Standardization: Pipette 25 mL of the 0.1M NaOH and transfer it into a clean conical flask,  to it add 2-3 drops of phenolphthalein indicator and titrate with 0.1N oxalic acid solution until color changes from purple to colorless. 

Reaction: 

H₂C₂O_4(aq)  + 2NaOH_(aq) → Na₂C₂O_4(aq) + 2 H₂O_(l) 

Factor Calculation: 

• 1 mole of oxalic acid ≅ 2 moles of sodium hydroxide 
• 1000 mL of 1M H₂C₂O₄ ≅ 80 g of NaOH 
• 1000 mL of 1M H₂C₂O₄ ≅ 40 g of NaOH 

1 mL of 0.1 M H₂C₂O₂.2H₂O ≅ 0.0040 g of NaOH

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