Purification of an Acid

This text describes the purification of an acid. The acid was first recrystallized from absolute alcohol, then dissolved in a small amount of water and sulfuric acid. The solution was extracted with purified ether and the acid was distilled under two millimeters pressure. The acid gave a slightly cloudy 0.32 normal solution, which was believed to be due to a non-ionic impurity.

Summary

• The purpose of the purification process was to remove impurities from the acid.
• The steps involved in the purification process were:
• Recrystallization from absolute alcohol
• Dissolution in water and sulfuric acid
• Extraction with purified ether
• Distillation under two millimeters pressure
• The physical constants and derivatives of the acid were:
• Melting point: 13.9 – 14°C
• Boiling point: 274° – 275°C at 763 mm Hg
• It readily forms a hydrate when standing in air. This melts at 30 – 36°C.
• The ethyl ester boils at 221°C.
• The amid melts at 114°C.

Questions

• What was the purpose of the purification process?
• What were the steps involved in the purification process?
• What were the physical constants and derivatives of the acid?