Difference Between Ammonia and Ammonium Hydroxide

Ammonia vs Ammonium Hydroxide

Ammonia and ammonium hydroxide have many uses for us. We all know that ammonia is a pungent smelling gas with a chemical formula NH3. When it comes in contact with water, what we get is ammonium hydroxide which is represented with the following chemical equation.

NH3 + H2O —> NH4+ + OH-

Ammonium hydroxide is also called liquid ammonia as it is nothing but ammonia gas dissolved in water. Ammonium hydroxide is very useful as it is easier to handle than ammonia gas. NH4 is ammonium ion while NH3 is ammonia gas. This is why ammonium oxide is also called NH3 (aq).

Both ammonia and ammonium oxide are very useful to us finding use in nutrition industry, pharmaceutical industry, fertilizers, and also as a cleaning agent. There are many similarities between ammonia and ammonium hydroxide as in essence NH4 is in effect liquid ammonia, but there are many differences also.

For starters, ammonia is a gas having a formula of NH3. It is made up of nitrogen and hydrogen molecules. Though it is a dangerous gas when inhaled, it is widely used as a cleansing agent and the worldwide usage exceeds millions of tons every year. To differentiate ammonia with ammonium hydroxide, it is also called anhydrous ammonia implying it does not contain any water. On the other hand, ammonium hydroxide is liquid ammonia or ammonia in water which is a solution that finds household applications.

Liquid ammonia is an excellent window cleaner and so extensively added to cleaning agents sold in the market. Interestingly, when ammonium hydroxide is used as a cleaning agent, we ask the vendor to give us ammonia. Liquid ammonia is also used in the meat industry for a process known as beefing.


• Ammonia is a gas while ammonium hydroxide is a liquid solution also called liquid ammonia as it is ammonia dissolved in water

• To differentiate chemically, ammonia is represented as NH3, while ammonium hydroxide is represented as NH3 (aq)

• NH3 is anhydrous, while NH4 has water