Properties of Solutions- Ammonia Fountain

Ammonia Fountain

An inverted round bottom flask with red liquid, glass tubing, and silicone tubing with an orange bulb. A ring stand holds the  flask above a beaker.

Description: The solubility of ammonia gas in water is demonstrated. A small amount of water is squirted into an inverted flask containing ammonia gas. The ammonia dissolves in water, creating a vacuum that draws in the phenolphthalein/water from below.

This demonstration is also available on video and JCE “Chemistry Comes Alive!”

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

Year: 1985  Vol: 2  Page: 205

Keywords: Ammonia gas, Water,  Vacuum, Phenolphthalein, Solubility, Intermolecular Forces

Rating:

Hazard: Medium

• Acute toxicity hazard – respiratory system
• Serious eye damage
• Skin corrosion hazard
• Inhalation hazard
• Aquatic toxicity hazard
• Germ cell mutagenicity
• Reproductive toxicity
• Implosion hazard

Effectiveness:  Excellent

• Deeply engaging
• Time to results is low
• High reliability
• Good connection from demo to course material
• Counterintuitive effects
• Results are observable without guidance

Difficulty: Medium

• Sequential manipulations
• Some intermediate steps to results
• Use of toxic reagents
• Simple procedures

Safety Precautions:

• Eye protection required
• Gloves required
• Perform in a well-ventilated area
• Absorbent material on hand
• Sodium bicarbonate on hand

Class: Gases, Solubility, Intermolecular Forces

Division: General

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