NaBr Lewis Structure& Characteristics: 17 Complete Facts

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NaBr is an inorganic bromide salt of sodium, similar to chloride salt of sodium. Let us study some facts about NaBr.

NaBr is an inorganic salt of the halogen series with a molecular weight of 102.9 g/mol. It is a white anhydrous solid packed in cubic crystal lattice with high solubility in H2O, methanol, ammonia solution. It can be prepared by passing HBr to NaOH solution and is hygroscopic in nature.

NaBr is widely used as a bromine source by reacting NaBr with chlorine gas and for certain crystal growth applications. Let us discuss more details and characteristics like shape, angle of NaBr.

How to draw NaBr lewis structure?

NaBr lewis structure is a simple electronic representation of bonds, lone pairs, valence electrons. Let us draw the steps required.

Counting the total valence electrons

The foremost step includes counting the total number of outermost electrons available in the valence shell orbitals. Ground state electronic configuration of Na and Br are [Ne]3s1 and [Ar]4s23d104p5. Na has 1 and Br has 7 making a total of 8 valence electrons.

Choosing the central atom

Na is chosen as the central atom. NaBr is a diatomic ionic molecule so the concept of choosing central atom does not make a literal sense in this context.

Forming the skeletal structure

Na and Br are drawn with their respective valence electrons in their surrounding and an electron transferred is shown from Na to Br. Skeletal structure is the electronic representation of the molecule before final construction of the lewis structure.

Drawing the final lewis dot structure

The electron pair between the atoms is drawn as the single bond and the remaining valence electrons are placed on Cl as lone pair of electrons. In doing so, the octet is fulfilled for both Na and Cl atoms.

nabr lambda
NaBr lewis structure

NaBr lewis structure resonance

Resonance structure is the canonical representation of delocalization of electron cloud in a system. Let us check the resonance form of NaBr.

The resonance structure of NaBr is zero with no pi bonds for delocalization of bonds. The single bond between Na and Br atom is fixed and forms a stable single bonded compound. Resonance structures are important for covalent compounds with pi bonds to maximize the stability of the structure.

NaBr lewis structure shape

The shape or structure of a molecule depends only on the bonded electron pairs. Let us discuss in details.

The shape of NaBr molecule is linear in shape with a single bond present between the atoms. The lone pairs do account for NaBr shape and remains localized on the respective atoms at a maximum distance to minimize repulsion among the lone and bonded electron pairs.

Shape of a molecule is highly affected by its equilibrium state and the energy possessed by the system in that state.

NaBr lewis structure formal charge

Formal charge is the hypothetical charge acquired by the atoms in a molecule if the electrons are fairly distributed in a system. Let us calculate the formal charge for NaBr.

Formal charge of NaBr = (Number of valence electrons in a free atom of the element) – (Number of unshared electrons on the atom) – (Number of bonds to the atom)

  • Formal charge of Na = 1-0-1 = 0
  • Formal charge of Br = 7-6-1 = 0
  • The overall charge of the molecule is zero and the respective atoms also has zero formal charge implying NaBr molecule is neutral.

NaBr lewis structure octet rule

Octet rule states that each atom takes up 8 electrons in its valence shell to acquire maximum core shell stability. Let us check if NaBr follows octet rule.

NaBr obeys octet rule by forming a stable and noble molecule. This takes place by transferring one electron by Na to Br. Br acquires noble gas type configuration by gaining one electron and Na adopts a noble gas configuration by losing one electron to Br.

If a molecule loses, gains or shares electrons in a way that results in a core shell type noble gas configuration with 8 electrons in its octet, then it follows octet rule.

NaBr lewis structure lone pairs

Lone pairs are the non bonded electron pairs that do not take part in hybridization. Let us calculate the lone pairs for NaBr.

NaBr lewis structure has a total 3 lone pairs. The 3 lone pairs are from Br and resides on it without involving in delocalization. Br takes up 1 electron from Na and forms the bond and the other 6 electrons of Br do not participate in bond formation.

NaBr valence electrons

Valence electrons are the outermost electrons that are loosely bounded to the nuclei and participates in bond formation. Let us calculate valence electrons for NaBr.

NaBr lewis structure has a total of 8 valence electrons available for lewis structure construction. 1 electron from Na is transferred to Br to form a bond and complete its octet. The remaining 6 electrons of resides on Br without delocalizing.

Ground state electronic configuration of Na and Cl are [Ne]3s1 and [Ar]3d104s24p5 and valence shells are 3s and 4s, 4p in Na and Br.

NaBr lewis structure angle

Bond angle is the angle formed between two bonds constituting to the same central atom. Let us discuss below.

NaBr has a bond angle of 1800 where the atoms are separated in a linear geometry fashion. Here the concept of hybridization and bond angle depending on it does not work in case of NaBr as the molecule is ionic in nature and not covalent.

NaBr hybridization

The hybridization of NaBr is sp3 with rock salt crystal lattice. Let us discuss in details.

NaBr has rock salt structure with sp3 hybridization. Na+ cations and Br– anions occupy faces, corners, edges and centers of the crystal cubic lattice. Rock salt structure sometimes corresponds to sp3 hybridization. In NaBr, it has single bond between Na and Br atoms formed by transfer of electrons.

NaBr is ionic and hybridization’s concept is for covalent solids to attain extra stability by overlapping of orbitals. Ionic compounds do not involve orbitals overlapping.

NaBr lewis structure
Rock salt structure of NaBr from wikipedia

Is NaBr solid ?

A solid state is a state of matter in which all the molecules are tightly packed giving a fixed shape. Let us discuss in details.

NaBr is solid state mostly due to high atomic mass of Br. This results in a dense packing state with greater van der waals forces of attraction. As such higher energy force is required to separate the discrete molecules in a densely packed white anhydrous crystalline state at high melting and boiling point.

Why is NaBr solid ?

In the following section, we shall discuss why NaBr is in solid state.

NaBr is solid as the halogen Br element places itself down in the group with greater atomic mass and the tendency of a compound to become solidified increases down the group in a periodic table.

Is NaBr soluble in water?

Hydration energy or solubility rate depends on how well the ions are packed together. Let us discuss in details.

NaBr is soluble in water as it is ionic and polar in nature that results in breaking down of the crystal lattice to respective cations and anions and surrounded by water molecules. This forms a strong ion-dipole interactions resulting in a high hydration energy sufficiently high to overcome lattice energy.

Why is NaBr soluble in water ?

Lattice energy is the energy released when a lattice breaks down in to respective ions. For a compound to be soluble in water, hydration energy > lattice energy.

NaBr is found to be soluble in water as it has high hydration energy as compared to lattice energy. The ions (cations and anions) and water forms strong interactions. The interaction between Na and Br in their crystal lattice forms is not so strong due to difference in sizes.

Is NaBr polar or nonpolar ?

A polar molecule contains charge separation and definite dipole moments’ magnitude. Let us check if NaBr is polar or not.

NaBr is polar as it has large electronegativity difference between Na and Br atoms. Since Br is more electronegative than Na (Na = 0.92 and Br = 3.2), it pulls the electron density from the bond between Na and Br towards itself. Further, they have charge separation with + and – charges on Na and Br.

Why is NaBr polar ?

In the discussion below, we shall learn why NaBr is polar in nature.

NaBr is polar due to charge separation resulting in partial positive and negative ends in the molecule. Polarity depends on distance between the charges and magnitude of charges which favors for the ionic solid to be polar in nature.

Is NaBr acid or base ?

An acid or a base produces conjugate base or conjugate acid when it is dissolved. Let us discuss in details.

NaBr is neither an acid or a base as it is formed by the neutralization reaction of mildly acidic hydrobromic acid, HBr and strong base NaOH. This reaction is called neutralization reaction and forms water and neutral salt, NaBr. It neither has acidic protons or basic hydroxyl ions.

Is NaBr an electrolyte ?

An electrolyte is formed by reacting acid and base that consists of cations and anions. Let us discuss in details.

NaBr is an electrolyte as it dissociates in to Na+ and Br– ions in solution. The cations and anions can move to opposite directions when electric current is passed through electrodes dispersed in solution. The degree of dissociation of NaBr in solution depends on the amount of ions formed in equilibrium.

Is NaBr a salt  ?

A salt is a chemical composition of cations and anions with balanced net charge. Let us discuss in details.

NaBr is a neutral salt formed during neutralization reaction of HBr and NaOH forming water as the side product and NaBr as the neutral salt.

Why is NaBr a salt ?

In the following section, let us understand why NaBr is a salt.

NaBr is a salt as it is formed from reaction of a mild acid and  a strong base. It is a neutral salt formed between metal-nonmetal and has no acidic proton or basic hydroxyl ion groups.

Is NaBr ionic or covalent ?

An ionic compound consists of ions held by electrostatic forces of interactions. Let us discuss in details.

NaBr is an ionic compound as it constitutes Na+ and Br– ions in their crystal lattice and the compound is formed by transferring of electrons and not sharing. Also, Na and Br have a great electronegativity difference resulting in partial displacement of electron cloud towards Br.

Why is NaBr ionic ?

In the following discussion, we shall understand why NaBr is ionic.

NaBr is ionic due to vivid electronegativity difference of 2.98 resulting in charge separation between the two ends of a molecule and large difference in size between the two radii. For a molecule to be ionic, it should have electronegativity difference greater than 1.7.

Is NaBr a molecular compound ?

A molecular or a covalent solid is formed between two non metals or non ionic species. Let us discuss below.

NaBr is not molecular as the compound is formed by reacting a metal and nonmetal. The atoms are ionic in nature and are held by electrostatic forces of attraction resulting in ionic compounds. The forces of attraction are covalent in nature in molecular compounds.

Conclusion

NaBr is an ionic, polar white crystalline solid with high melting and boiling point widely used as a source of bromine and widely used in oil and drilling industries.

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