Question

What are the criteria for purity of a solid?

Answer 1

Answer:

However for practical purpose in laboratory only melting point and boiling point are used as criteria for purity. A pure organic solid has a definite and sharp (sudden, rapid and complete) melting point, while an impure substance has a lower and indefinite melting point.

Answer 2

Answer:

• i. A chemically pure compound' has characteristic physical properties such as crystalline for refractive index, specific gravity, density, sharp melting and boiling point etc.
• ii. The magnitude of these properties change depending upon the nature and the amount of impurities present.
• iii. Presence of impurities lowers the melting point of solids and increases the boiling point of liquid.
• iv. Thus, melting point of a solid and boiling point of a liquid are important criteria of purity.