Ammonium Nitrate in Water

DESCRIPTION:
When ammonium nitrate is dissolved in water it feels cold, which indicates an endothermic reaction.
NH4NO3 (s)  → NH4+ (aq) + NO3- (aq)

TOPICS COVERED:
- endothermic reactions
- dissolution
- solubility
- energy transformations

MATERIALS NEEDED:
- 125mL Erlenmeyer flask w/ 30mL of water
- 3g NH4NO3

PROCEDURE:
1. Add NH4NO3 to the flask
2. Swirl to dissolve

ADDITIONAL COMMENTS:
This demo is great for students to do themselves.

SAFETY:
Safety goggles should be worn at all times.

REFERENCES:
Shakhashiri, B.Z. Chemical Demonstrations;  University of Wisconsin Press: Madison, 1983; Vol. 1, pp 8 -9.

Handout

This lesson plan‘s topic is the Evidences of Chemical Reactions. Students learn the various evidences, then they get a change to practice identifying them with a hands on activity. Ammonium Nitrate in Water is used in the activity portion of this lesson.