Best Overview: Is NH4+ Polar or Nonpolar? - Science Education and Tutorials

Ammonium ion (NH4+) is the simple salt of ammonia (NH3) which is positive in charge. Ammonia (NH3) is a polar molecule. Now, students of chemistry used to ask ” Is NH4+ polar or nonpolar?”, “NH4+Lewis structure”, and “NH4+ molecular geometry”. In this post, we try to answer these questions in the detailed manner.

The ammonium ion (NH4+ cation) has the molecular chemical formula NH4+ and is a positively charged species in an aqueous solution. Now the question is “what is acid and base?”. There are different ways to define them. In the aqueous solution, it can be defined as follows.

Arrhenius definition

Arrhenius give first definition about acid and base. He defined the as

” The chemical species gives proton is acid and the species accept the proton are called base in aqueous solution”
Arrhenius definition

It is a very good definition for an aqueous system. Hydrogen Chloride (HCl) is acid. Another name for this chemical is hydrochloric acid. HCl is present in the aqueous solution. On the other hand, ammonia is the base. Ammonia is a gas in normal atmospheric conditions. But it is soluble in water. Is the polarity of ammonia(NH3) influence the reacitity? check our earlier post on NH3 polar or nonpolar.

If we mix both HCl and ammonia (NH3) solution, it undergoes a neutralization reaction. What is a neutralization reaction?. In the aqueous solution, acid and bases reacted with each other in a faster way, forms salt and water. This reaction works well in an aqueous saystem. But there is a nonaqueous solution also there in nature.

Ammonia is soluble in water. so we can can write it as follows

NH3 + H2O ——-> NH4+OH-

Ammonia diisolves in water gives ammonium hydroxide (NH4+OH-). Then ammonium hydroxide reacts with hydrochloric acid, gives ammonium chloride salt and water as an outcome,

HCl + NH4+OH- —neutralization reaction——> NH4+Cl- +H2O

The protonation of the ammonia molecule produces the ammonium ion. Many of you may be unsure about the polarity of the ammonium ion. So, in this post, we discuss whether or not the ammonium ion is polar, as well as its properties and applications in day-to-day life.

Is NH4+ Polar or Nonpolar, then? Because of its tetrahedral form, NH4+ (ammonium ion) is nonpolar in nature. Since all four hydrogen atoms are symmetrically bound to the nitrogen atom in the tetrahedral geometry, the polarity of the N-H bonds is canceled, yielding a nonpolar NH4+ molecule. But NH3 molecule is polar.

The protonation of ammonia produces the ammonium ion (NH4+). As ammonia reacts with proton donors hydrochloric acid (HCl), it produces ammonium cation as mentioned above. The ammonium ion is oxidized when one hydrogen atom is removed for the cation, resulting in the formation of an ammonia molecule from an ammonium ion. This is the type of decomposition of NH4+ ion. Generally, it takes place at high temperatures.

The amount of ammonium ions (NH4+) produced by ammonia is determined by the pH value of the reaction solution. If the pH value is low, then the solution contains more H+ ions in the reaction solution. When ammonia undergoes a reaction with hydrochloric acid, it gives more amount of ammonium ions.

Ammonia dissociates into ammonium ions when dissolved in water as mentioned above. The equilibrium reaction of ammonia in water is shown in the diagram below.

H2O (water) + NH3 (ammonia) ⇌ OH− (hydroxideion) + NH4+ (ammmonium ion)

As previously stated, the concentration of ammonium ions in a solution is determined by the pH value of the solution. It implies that if the solution’s pH value is low, the formation of ammonium ions is higher, implying that equilibrium shifts in the right direction.

If the solution’s pH value is higher, then the reaction mixture contains more hydroxide ions. The hydroxide ion removes the hydrogen atom from ammonium ions to form ammonia, shifting the equilibrium to the left side of the reaction.

The chemical structure of the ammonium ion (NH4+) is made up of four hydrogen atoms and one nitrogen atom in the tetrahedral molecular geometry. The nitrogen atom is in the middle, surrounded symmetrically by four hydrogen atoms in a tetrahedral geometrical arrangement.

Nitrogen has an electronegativity of 3.04, while hydrogen has an electronegativity of 2.2. The polarity across the N-H bond is created by the difference in their electronegativity. As a consequence, the N-H bond in the NH4+ molecule is polar. NH4+ ions have a dipole value that is not zero.

However, the dipoles cancel each other out due to the symmetrical structure of N-H bonds, resulting in a nonpolar molecule.

Is NH4+ Polar or Nonpolar

Transferring hydrogen ions from hydrogen chloride to the lone pair of electrons in the ammonia molecule produces the ammonium ion (NH4+). Ammonia donates its lone pairs of electrons and H+ ion accepts it. What are ammonia and H+?

Lewis acid and Lewis base:

What is Lewis acid and Lewis base? Lewis acid and base definition differ from Arrhenius definition. But it is applicable in all form of material. We can apply in gas, solid, aqueous, and nonaqueous system also.

” The chemical species which accept the electron is called Lewis acid. The chemical species which donate the electron is called Lewis base”
Lewis acid and base definition

The positive charge of the ammonium ion (NH4+) is present in a number of salts, including ammonium chloride, ammonium sulfate, and ammonium carbonate. When it comes to solubility, the ammonium salt is soluble in water, but nitrate ammonium salts are not. The solubility product of ammonium nitrate salt is low in value. That is the reason, it is not soluble in water.

If you are wondering that is NH4+ polar or nonpolar, this article will help you clarify all your confusion.

Difference Between Polar and Nonpolar Molecules?

The molecules that are covalently bound to each other may have a charge distribution that is both unequal and equal across their atoms in an unsymmetrical manner. A molecule’s polarity is determined by a number of physical parameters, which we’ll go over one by one.

Polar molecules are those that have produced poles inside the molecule. Positive and negative charge terminals are the two poles in the molecule.The charge density distribution on the atoms in these molecules is not uniform.

If the electronegativity of two covalently bound atoms differs, they form a polar bond. For example N-H bond polarity in NH4+ is high in the value.A negative pole is formed by a higher electronegative atom, while a positive pole is formed by a lower electronegative atom in NH4+ tetrahedral molecular geometry.

The net dipole moment of such molecules has a value that is not zero. BeCl2, NH3, and other polar molecules are examples. You should look into the explanation for BF3’s polarity.

Nonpolar Molecules: There are no poles formed by these molecules across it. if it formed also, may canceled each other.In these molecules, the charge distribution over the atoms is uniform in tertrahedral geometry of NH4+ ion.

If the electronegativity of both atoms is identical, the covalently bound atoms form a nonpolar bond. But in our case, the electronegativity value of hydrogen and nitrogen of ammonium ion are not same. There is a definite difference in electronegativity value between nitrogen and hydrogen in the ammonium molecule. This is due to the fact that all atoms have the same proportion of charge.

It’s also conceivable that a nonpolar molecule contains polar bonds, but their polarity cancels out due to the geometrical symmetry of the molecule. N-H bond in ammonium NH4+ molecule is polar in nature. But the the entire NH4+ ion is nonpolar.

Some example of nonpolar molecules is CH2Cl2, XeF4, etc. You can check out the reason for the polarity of SF4 .

Is NH4+ Polar or Nonpolar

Since the arrangement of ammonium ions (NH4+) is tetrahedral geometry, all of the hydrogen atoms in NH4+ are grouped symmetrically around four corners of the central nitrogen atom, NH4+ is a nonpolar molecule. Since it is an ion with one missing electron in the central nitrogen atom, this molecule has many polar properties.

Since all hydrogen in the corner of the tetrahedral geometrical structure is the same, ammonium ions (NH4+) are nonpolar molecules. There’s no need for protons or hydrogen to be arranged differently because they’re all arranged the same way as in the normal tetrahedral structure.

The nonpolar molecule ammonium ions (NH4+)

All four hydrogen atoms in a tetrahedral structure are arranged in a systematic manner, bonded to the nitrogen central atom in the tetrahedral geometry, and cancel out the N-H bond polarity in all four directions, resulting in NH4+ becoming nonpolar.

In this blog, you will get more information about the polarity of BeCl2, NH3, SF4, BF3, CH2Cl2, the definition of polar vs nonpolar, and Lewis structure of water.

Why is NH4+ nonpolar?

The nitrogen atom is at the middle of the tetrahedral geometry, and all four hydrogen atoms are arranged in the four corners, as shown in the figure. The molecular geometry of NH4+ plays an important role in the polarity of the molecule.

The N-H bond has a definite dipole value, but all four dipoles are pointing in opposite directions to each other in the tetrahedral geometry, and the four dipoles cancel each other out due to the NH4+ molecule’s symmetrical tetrahedral structure form, making NH4+ is a nonpolar molecule.

As a result of the above discussion, even though an NH4+ ion molecular species contains polar N-H bonds, it is possible for it to be nonpolar since the dipoles cancel each other out. Lets discuss about the molecular geometry of the NH4+ molecule.

NH4+ Molecular Geometry

The NH4+ molecule has a tetrahedral structural form. The total number of valence electrons in NH4+ is eight (Octet rule), with four electrons and four hydrogens occupying the tetrahedral corner. The central nitrogen atom’s bond pairs increase to four due to the addition of one more hydrogen atom, and the lone pairs on the nitrogen atom are zero.

The total number of valence electrons in the NH4+ is nine, with five electrons from nitrogen and four hydrogens, but due to the positive charge (1+) on the NH4+ molecule, one electron is lost, making the total number of valence electrons eight.

The electron geometrical structure in methane and ammonium is the same, so the form of the ammonium ion structural geometry is considered the same as that of methane.

NH4+ Lewis and Geometrical Structure

Nitrogen has five valence electrons in its outermost shell and requires three more to complete its octet rule. Hydrogen atom, on the other hand, has one valence electron and needs an additional electron to be a stable NH4+ molecule.

As a result of this, each of the four hydrogen atoms in the tetrahedral geometry shares a single electron with the central nitrogen atom. All four hydrogen in NH4+ geometry is stabilized as a result of this. The nitrogen atom has (5 + 4) electrons, resulting in a total of 9 electrons in the outermost valence shell, and the + sign on NH4+ indicates that it has lost one electron. Now, the total valence outermost shell electron in the nitrogen atom is eight.

Since the nitrogen atom is in group 5 of the periodic table, it has five valence outermost electrons. The hydrogen atom belongs to group 1 in the periodic table, and we have four hydrogen atoms in the NH4+ molecule, so multiply it by four to get 5+1(4) = 9.

If you see a plus sign somewhere in the above calculation, it means one valence outermost electron has been lost, so 5+1(4)-1=8 means we have a total of 8 valence outermost shell electrons. The number of hydrogen atoms is four, and it is normally found around and on the outside of the nitrogen central atom. Since we have eight valence electrons in the outermost valence shell of NH4+ molecule, you must enter 2,4,6, and 8. If you don’t know how to draw the Lewis structure of NH4+ theoretically,

So, with nitrogen in its outermost valence shell, total electrons become 9-1 = 8 electrons, making the octet rule complete. This octet rule gives a stable structure. The nitrogen atom in the NH4+ molecule is also stabilized as a result of this. All the four N-H bonds in NH4+ ion are arranged in a tetrahedral pattern. H-N-H has a bond angle of about 109.5 degrees which pure tetrahedral structure.

Each of the four N-H bonds in NH4+ ion is symmetrical to the others. The geometrical and Lewis Structural form of the ammonium ion (NH4+) is depicted in the figure.

For more detailed information about Lewis structure of similar ammonia molecule, you can go thorough an article on Lewis structure of NH3.

Parameters that determine the polarity of NH4+ molecule

To determine whether a NH4+ molecule is polar or nonpolar, a few parameters are needed to make the polar or nonpolar. Let’s take a look at each one of these parameter separately on the NH4+ molecule.

Electronegativity of NH4+:

The term electronegativity refers to an nitrogen atom’s ability to draw a bound electron pair to one of its sides in the ammonium (NH4+) molecule ion.The distinction between their electronegativity value of nitrogen and hydrogen, vice versa is ensured by the polarity of a covalent N-H bond formed between nitrogen and hydrogen atoms in ammonia (NH4+) molecule ion.

The electronegativity value difference between the nitrogen and hydrogen atoms that make up a NH4+ molecule determines its polarity. Four N-H bond in ammonium (NH4+) molecule ions are polarised in nature. But as mentioned above, NH4+ molecule ion is nonpolar.

Dipole Moment of NH4+:

An ammonium (NH4+) molecule’s polarity is measured by dipole of nitrogen and hydrogen atoms. The total dipole of a polar molecule is still greater than zero.

Nonpolar molecules, on the other hand, have a net dipole equal to zero. In ammonium (NH4+) molecule ion is nonpolar in nature. Because of its dipole moment of N-H bond is high in value. Its SI unit is the Debye, which is represented by the letter D. The dipole of Ammonium (NH4+) ion is also 0 D.

Do you realise how critical the dipole moment of ammonium ion is ? That the dipole moment of ammonium molecule ion shows us where the electrons are in the molecule. Many properties, such as boiling point and melting point of chemical compounds, are dependent on the molecular dipole moment .

Geometrical Shape of NH4+:

If a NH4+ molecule’s form is symmetric tetrahedral geometry, it tends to be nonpolar in nature, whereas asymmetric NH3 molecules tend to be polar. You can check on the post of NH3 polarity.

Similarly, the polarity of all four N-H bonds is canceled out by the symmetrical tetrahedral form of the ammonium ion(NH4+).

Molecular Hybridization Of NH4+:

Since the nitrogen atom in the ammonium molecule ion has just four N-H bonding orbitals, the hybridization of ammonium ion (NH4+) is SP3. Tetrahedral geometry is SP3 hybridization. Here in ammonia molecule have four sigma N-H bond as shown in the figure.

NH4+ Bond Angle:

Since ammonium ( NH4+) molecule has a tetrahedral geometrical structure and NH3 has three hydrogens surrounding the central nitrogen atom, the bond angle of the ammonium ion (NH4+) is greater than that of NH3 molecule. Since the lone pair’s location isn’t as good as the unit lonepair’s, it takes up more room, compressing and shrinking the rest of the conformation of ammonium (NH4+) molecule, is less than the angle of the H-N-H unit in NH4 +.

So a lone pair is less localized rather than bonding pair in ammonia (NH3) molecule, which takes more space and resulting H-N-H bond angle than in NH4+ molecule.

Properties of NH4+

Ammonium (NH4+)molecule ion has a molecular mass of 18.039 g/mol.
Over the ammonium (NH4+) molecule ion, the formal charge is + 1.
It has a pH of 9.25. It is basic in nature due to the formation of more hydroxide cion in the above said equilibrium.
This ammonium cation has a tetrahedral geometrical molecular form with SP3 hybridization.

Uses of NH4+

Ammonium ions and the compounds they produce are commonly used in fertilizer production in the chemical industry.
Ammonium compounds are widely used in pharmaceuticals and the garment industry.
While it is an essential source of nitrogen for many plant species, it is harmful to the majority of crop species. Directly we should not use ammonium on crops.
Different factories manufacture NH4+ ion, which is used as a fertilizer in agriculture. It is used in the purification of water sources.

Conclusion

The ammonium (NH4+) ion has a tetrahedral geometrical structure form, which means that all of the N-H bonds are symmetrically arranged over the nitrogen atom. The electronegativity value of nitrogen and hydrogen atoms differs. As a consequence, the N-H bond is polar, resulting in a dipole moment of the N-H bond is not zero.

However, due to the symmetrical form of the ammonium (NH+) ion, the dipoles of N-H bonds cancel each other out, resulting in the nonpolar NH4+ molecule ion. The NH4+molecule ion has eight valence outermost shell electrons. The hybridization of ammonium ion (NH4+) is sp3 hybridized, and the H-N-H bond angle is 109.5 degrees.

FAQ on “Is NH4+ polar or nonpolar?”

Is NH4+ Or NH3 Stronger

Since oxygen is more electronegative value than nitrogen, NH3 is stronger than NH4+. If the acid is weaker, it will have a larger conjugate base. Because of the smaller atomic scale and lone pairs of electrons on nitrogen, the NH3 is a weak base as compare to hydroxide ion.

Is NH4+ Basic Or Acidic?

According to the Bronsted-Lowry theory, NH4+ is acidic since it can donate a proton to other molecule such as the hydroxide ion or water. According to Lewis’ theory, NH4+ is neither basic nor acidic since there is no space for electron pairs to be received, and there are no donated electrons.

Is it safe to clean with ammonia?

Yes, ammonia is safe for cleaning; however, it is best used to clean burned-on food from floors, microwaves, and ovens. It can also be used to disinfect mirrors and windows. When it comes to price, it is considered to be very low in comparison to other cleaners. But ammonia creates an intense odor.

How do you identify NH4+?

If you want to detect ammonium ions, apply a dilute sodium hydroxide solution to the mixture and gently heat it. It means ammonium ions are present if it converted it to ammonia gas. Choking odour may also be used to identify ammonium ions.

If you bring concentrated hydrochloric acid dipped glass rod, it forms white precipitate with ammonia gas. This white precipitate in the glass rod is nothing but ammonia ions.