Question

When ammonium chloride crystals are dissolved in water, the temperature of the water decreases. What does the temperature change indicate about the dissolving of ammonium chloride in water.

Answer 1

Answer:

See Explanation

Explanation:

A decreasing temperature indicates that the dissolution process for the ammonium chloride requires input of energy from surroundings. That is, the process is essentially 2 parts => system (object of interest - NH₄Cl) and the surroundings (everything else - solvent - H₂O). The surroundings (water) solvent is showing a measured decrease in temperature or loss of energy (exothermic to surroundings) which flows into the system (NH₄Cl) and effects dissolution of salt into solution (endothermic to system).