Cesare Cesare 1 1 gold badge 2 2 silver badges 9 9 bronze badges. Ammonia could act as a really weak acid. Add a comment. Active Oldest Votes. Improve this answer. Broklynite Broklynite 1 1 silver badge 7 7 bronze badges.
Sign up or log in Sign up using Google. Sign up using Facebook. Sign up using Email and Password. Post as a guest Name. It is one of the important sources of nitrogen for plants and animals. Exposing to open air, liquid ammonia will quickly turn into a gas. Ammonia is easily liquified due to strong hydrogen bonding between molecules.
In this article, we will discuss Is Ammonia NH 3 acid or base? Is it strong or weak? Its conjugate acid-base pairs, etc. So, Is NH 3 an acid or base? However, NH 3 can act as acid as well depending on whom it reacting with but primarily, ammonia has a nature of weak base. A base is defined as a proton acceptor or lone pair donor.
The production of hydroxide ions on dissolving in an aqueous solution shows the basic nature of ammonia. Theoretically, we have three acid-base theories to know whether NH 3 is acid or base. According to Arrhenius theory, the compound is said to be Arrhenius base when it produces OH — ion through ionization or through dissociation in water and increases the concentration of OH — ions in an aqueous solution.
Or a compound is said to be Arrhenius base when substance contains at least one unit of OH — in the chemical formula and produces OH — ions in water. Clearly, when NH 3 is dissolved in an aqueous solution it accepts the proton from the water molecule and produces OH — ion, and from the point of first Arrhenius definition, NH 3 will act as Arrhenius base as it is able to increase the concentration of OH — in the final solution.
Bronsted-Lowry theory:. According to the Bronsted-Lowry theory, a compound is said to be base when it accepts the proton from other compounds and forms the conjugate acid. Or you can say proton acceptor compounds are classified as Bronsted-Lowry base. Take an example to understand whether NH3 base or acid according to the Bronsted-lowry theory-.
Lewis theory:. Here comes the most important concept of acid and base. According to the lewis theory, a compound is said to be acid when it accepts the pair of electrons and a compound is said to be base when it donates the pair of electrons. The ammonia molecule consists of nitrogen as a central atom that contains two lone pairs of electrons that can be quickly donated to lewis acid because the nitrogen atom is less electronegative, hence, it is always ready to give up the electrons.
To know whether Ammonia NH 3 is a strong base or weak, you must know the basic difference between a strong base or a weak base. Strong base: A compound is a strong base when it completely dissociates in an aqueous solution and liberates a large number of hydroxide ions.
All moles of the strong base dissociate into hydroxide ion OH — and no part remains undissociated into the solution. Weak base: A compound is a weak base when it partially or not completely dissociate in an aqueous solution which means not all moles of the base dissociate in a solution to yield OH — ion, and at equilibrium, both undissociated base and their ionized product present in the solution. So, Is Ammonia NH 3 a strong base or weak? NH 3 is considered a weak base because when it is dissolved in an aqueous solution then not all the molecules of it react with water to yield OH — ions, very few molecules of NH 3 react with water molecule ions and produce OH — ion in the solution.
Therefore, the amount of OH — ions produced in an aqueous solution is very low as compared to the number of NH 3 moles we dissolved in the solution. The double arrow in the reaction of ammonia and water shows that both forward and backward reactions occur at equilibrium.
Hence, not all the NH 3 molecules react with water ions and produce OH — ions, most of them just stay as NH 3 , only, a few molecules do interact with water, therefore, ammonia is considered a weak base in nature. More reasons, why is NH 3 is considered a weak base? Ammonia has a very small value of base dissociation constant K b. The higher the value of K b , the more the base dissociates. Also check:- How to tell if the acid or base is strong or weak?
So, Is NH 3 also act as an acid? Ammonia NH 3 can act acid only in one condition when the reacting compound is more basic than it e. This is because a stronger base more dissociates in an aqueous solution and strongly accepts the proton.
Therefore, when NH 3 reacts with a stronger base like OH — , it is left with no choice and has to release a proton. Account Settings. Is ammonia basic? Ammonia Pipe Marking. Similar Questions What is ammonia made out of? Is ammonia safe to use? How does anhydrous ammonia work? What is anhydrous ammonia? What are the dangers of ammonia exposure? What is anhydrous ammonia used for?
Is ammonia flammable? What are the limits for exposure to concentrated ammonia? This trigonal pyramidal shape provides the molecule with a dipole moment and makes it a polar molecule. Due to the presence of a lone pair, it has the ability to form hydrogen bonds in water. As explained earlier, NH3 is a weak base and reacts with acids to form salts.
Although NH3 is a weak base, it also acts as a weak acid under certain conditions and reacts with bases. NH3 also perform self dissociation and carries out redox reaction under certain conditions. Below is the reaction where NH3 forms its conjugate acid and conjugate base simultaneously. NH3 undergoes exothermic combustion to produce Nitrogen gas and water vapor.
Following is the combustion reaction of NH3. Although Nitrogen oxides are unstable with respect to N2 still we can form Nitrogen oxides with the help of some catalysts. Example of such a reaction is:.
The combustion of NH3 is always done in the presence of a catalyst due to the high heat of vaporization and ignition temperature. Platinum gauze is one of the catalysts used in the NH3 combustion reaction.
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