Properties of Solutions- Crystallization from Supersaturated Solutions of Sodium Acetate

Crystallization from Supersaturated Solutions of Sodium Acetate

Description:

A) A supersaturated solution of sodium acetate is crystallized by pouring it onto a seed crystal, forming a stalagmite-like solid.  Heat is radiated from solid.

B) A crystal is dropped into a test tube, forming thin monoclinic crystals. This may be illuminated from below; heat is radiated from the solid.

This demonstration is also available on video and JCE Software “Chemistry Comes Alive!”  Vol. 2 CD-Rom.

Source: Shakhashiri, B.Z. Chemical Demonstrations: A Handbook for Teachers of Chemistry

Year: 1983  Vol: 1  Page: 27

Keywords: Crystallization, Sodium acetate, Exothermic, Solutions, Supersaturated

Ratings:

Hazard: Some

• Use of mildly reactive chemicals
• Electric shock hazard

Effectiveness: Good

• Results are clearly observable without guidance
• Time to results is low
• Good connection from demo to course material
• Moderate reliability

Difficulty: Medium

• Some intermediate steps to results
• Careful manipulations are required
• Reactions at non-standard conditions
• Demos in which a display is used

Safety Precautions:

• Eye protection is required
• Gloves are required
• Use chemically inert surface
• Use UL approved three-prong plug and outlet

Class: Intermolecular Forces, Chemical Equilibrium, Thermodynamics, Liquids and Solids, Phase Changes

Division: General

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