ammonia vs. ammonium

ammonia

[ uh-mohn-yuh, uh-moh-nee-uh ]show ipa

noun

1. a colorless, pungent, suffocating, highly water-soluble, gaseous compound, NH3, usually produced by the direct combination of nitrogen and hydrogen gases: used chiefly for refrigeration and in the manufacture of commercial chemicals and laboratory reagents.
2. this gas dissolved in water; ammonium hydroxide.

ammonium

[ uh-moh-nee-uhm ]show ipa

noun

1. the univalent ion, NH4+, or group, NH4, which plays the part of a metal in the salt formed when ammonia reacts with an acid.