Explain why ammonia is more volatile than ammonium ion? Thanks for your help.?

Answer 1

The ammonium ion NH4+ is just ammonia gas NH3 dissolved in water. Once ammonia is ionized and bound to water, it is not going anywhere. You have converted a gas into a liquid solution. By definition a liquid is less volatile than a gas.

You could say that ammonium has one more hydrogen and therefore heavier, and is a positively charged ion, but relating that to volatility is not straightforward.

Ammonia gas boils at -33 degrees C, so at room temperature it is a gas.

Water boils at 100 degrees C. So at room temperature it is a liquid.

By definition, a substance that is a gas at room temperature is completely "volatized" or evaporated. A substance that is liquid at room temperature (like NH3 dissolved in water) is not volatile, although some vapor does evaporate.

So you are just asking why a gas is more volatile than a liquid.

No one really knows why, but people try to come up with creative explanations nonetheless based on chemical structures, molecular dynamics, quantum theory, etc.

Saying "intermolecular forces in a gas are weaker than in a liquid" is always a good fallback.

So something along the lines of "the intermolecular forces in ammonia are much weaker than the intermolecular forces binding ammonia to water" would be suitably impressive, although not particularly enlightening or useful.

Answer 2

Ammonia is a gas in which three hydrogen atoms are covalently bonded to a nitrogen atom. The intermolecular forces are weak and so ammonia exists in the gaseous state.

the ammonium ion is formed by dative or coordinate bonding beween an ammonia molecule (which has a lone pair of electrons) and a proton (H+) so the species (the ammonium ion) becomes +vely charged - (NH4)+ . this +vely charged ammonium ion behaves, for all intents and purposes as a metallic ion and associates with anions but electrostaic forces. as a result the ion exist in solution and the solid state and is not as volatile.

Answer 3

Ammonium ion will not exist as the free ion outside of aqueous solution, existing only in a compound (e.g. NH4Cl), which will most likely be a solid. NH3 is a gas at room temperature.

Answer 4

Ammonium is a cation and can form strong ion-dipole interactions with the solvent (eg. water). On the other hand, ammonia is a polar neutral molecule which forms weak van der Waals interactions and hydrogen bonding with water. Hence, it is more volatile.

Answer 5

ammonia is a gas whereas the ammonium ion is either part of a solid compound or in a solution of an ammonium compound (like ammonium chloride)

Answer 6

no idea