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.
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.