The schematic illustration of valence electrons of any molecule in the form of line and dots are known as lewis’s structure. Let us discuss the CaI2 lewis structure.
CaI2 lewis structure is the combination of metal and non–metal. It has 1 Ca atom (metal) and 2 I atoms (non–metals). Ca is least electronegative than I. Thus the Ca metal gets the central position. It is bonded with 2 I atoms with 2 ionic bonds. Ca atom gives its 2 valence electrons to 2 I atoms.
The +2 charges develop on Calcium metal. 2 iodine atoms accept 1 electron each from the Ca atom and have a -1 charge. All the 2 I and 1 Ca atoms are placed in a square bracket due to the charge on it. Some more topics like CaI2 lewis structure formal charge, the octet rule, resonance, and shape are discussed in brief below.
How to draw CaI2 lewis structure?
Below are the steps and rules given to draw the (calcium iodide) CaI2 lewis structure.
Valence electrons and bonding within CaI2:
Evaluate the total number of valence electrons present on the CaI2 lewis structure by adding the valence electrons of each I and Ca atom present in it. CaI2 has strong ionic bonding due to the loss and gain of electrons between metal (Ca) and non – metal (2 I) atoms.
Octet rule and lone pair electrons in CaI2:
Mark or count the lone pair electrons present on the CaI2 lewis structure after bonding. Also, apply the octet rule to identify whether all the atoms have complete or incomplete, or extended octets.
Evaluate formal charge and shape of CaI2:
Determine the formal charge present on all the Ca and 2 I atoms by applying the given formula of a formal charge. Also predict the shape, hybridization, and bond angle of CaI2 lewis structure.
CaI2 valence electrons
The outermost shell electrons of any atom, element, or molecule are called valence electrons. Below is the brief discussion on CaI2 lewis structure valence electrons.
CaI2 lewis structure contains a total of 16 valence electrons. Calcium metal belongs to the 2nd group and the Iodine atom belongs to the 17th group of the periodic table. They both have 2 and 7 valence electrons and have outer valence electronic configuration of Ca and I is 4s2 and 4d10, 5s2, 5p5.
The detailed steps of the calculation of CaI2 valence electrons are given below.
- Valence electrons of Ca metal and I atoms is = 2 x 1 (Ca) + 7 x 2 (I) = 2 + 14 = 16
- CaI2 lewis structure has total valence electrons = 16
- Total electron pair on CaI2 is identified by dividing valence electrons of it by 2 is = 16 / 2 = 8
- Therefore, the CaI2 lewis structure has a total of 16 valence electrons and 8 electron pairs.
CaI2 lewis structure lone pairs
Non–bonding or unshared electrons after bonding in a molecule or compound are known as lone pair electrons. Take a look at the description of the CaI2 lone pair electron.
CaI2 lewis structure 6 lone pair electrons. There is a total of 16 valence electrons of CaI2. 4 electrons are engaged in 2 Ca – I bond formation thus being bond pairs. 12 unshared electrons are present on 2 I atoms. Each I atom contains 6 unshared electrons i.e. 3 lone pairs on each I atom present.
The calculation for lone pairs on both Ca and I of CaI2 lewis structure is given below:
- Lone pair electrons = Valence electrons (V. E) – Number of bonds / 2
- Central Ca metal has lone pair electron = 2 (V. E) – 2 (Ca – I bonds) / 2 = 0
- Outer I atom has lone pair electron is = 7 (V. E) – 1 (Ca – I bond) / 2 = 6 / 2 = 3
- 2 I atoms lone pair electron = 3 x 2 = 6
- Hence, the central Ca atom has zero lone pair electrons and the 2 I atoms have 6 lone pair electrons in the CaI2 lewis structure.
CaI2 lewis structure octet rule
The existence of 8 electrons in the outermost orbit of an atom shows its stability is explained by the octet rule. Let us discuss the application of the CaI2 lewis structure.
CaI2 lewis structure has complete octets of both iodine atoms and incomplete octets of central Ca atom. The central Ca atom donates both electrons to form 2 Ca – I ionic bonds. Thus it is surrounded by only 4 bonding electrons and shows an incomplete octet.
The two iodine atoms gain one electron from the central Ca atom. Thus they get surrounded by 8 electrons. Therefore both the iodine atoms show complete octets in the CaI2 lewis structure.
CaI2 lewis structure formal charge
The loss or gain of electrons in an atom that gives a positive or negative charge to it is called the formal charge. A discussion on the CaI2 formal charge is given below.
Formal charge of CaI2 lewis structure is = (valence electrons – non-bonding electrons – ½ bonding electrons)
The below table shows the detailed calculation of the CaI2 lewis structure formal charge.
| Atoms of CaI2 lewis structure | Valence ‘ electrons on I, Ca, and I | Non – bonding electrons on I, Ca, and I | Bonding electrons on I, Ca, and I | The formal charge on I, Ca, and I |
| Outer Iodine (I) atom | 07 | 08 | 00 | ( 7 – 8 – 0 / 2 ) = – 1 |
| Central Calcium (Ca) atom | 02 | 00 | 00 | ( 2 – 0 – 0 / 2 ) = + 2 |
| Outer Iodine (I) atom | 07 | 08 | 00 | ( 7 – 8 – 0 / 2 ) = – 1 |
CaI2 lewis structure shape
Molecular atoms have packaging or arrangement in a particular manner that forms geometry or structural shape. Let us have some discussion on CaI2 lewis structure shape.
CaI2 lewis structure has a linear shape. All the Ca and I atoms are arranged in a linear form or the same plane. The central Ca atom doesn’t contain lone pair so there is no repulsion or distortion in its geometry. Also, it follows the AX2 generic formula of VSEPR theory that confirms its linear shape.
CaI2 hybridization
Overlapping of atomic orbitals of a molecule to produce a new hybrid orbital with similar energy is known as hybridization. Below is the explanation of CaI2 hybridization.
The CaI2 lewis structure contains a central Ca atom with ‘sp’ hybridization. As the Ca atom has steric number 2. The Steric number of Ca atom is found as = number of atom bonded to Ca + lone pair on Ca i.e. 2 + 0 = 2. Thus the VSEPR theory says that a compound with steric number 2 is ‘sp’ hybridized.
There is the mixing and recasting of atomic orbitals of the central Ca atom in the CaI2 molecule. The one ‘s’ and one ‘p’ orbital of the Ca atom get overlap with each other and form a new ‘sp’ hybrid orbital having similar energy as before overlapping.
CaI2 lewis structure angle
The angle within any two immediate bonds of any molecule is known as the bond angle. Let us have a brief discussion on the CaI2 lewis structure bond angle.
CaI2 lewis structure has an 1800 bond angle within its immediate bonds. According to VSEPR theory for molecular structure, the CaI2 lewis structure comes under the AX2 generic formula. Here, A = central Ca atom and X2 = 2 bonded I atoms. So, it has linear geometry with an I-Ca-I bond angle of 1800.
Is CaI2 solid?
Solid is a state of matter that has a particular shape due to the closed packing of atoms with definite mass and volume. Let us have some discussion on CaI2‘s solid nature.
CaI2 compound is a white color solid compound. Rather it is a deliquescent solid due to its ability to convert into a liquid if comes in contact with air. It has a closed packing of Ca and I atoms that form a rhombohedral crystal structure. Also, it has octahedral coordinate geometry.
How CaI2 is solid?
CaI2 is a solid as it has the closed packing Ca and I in rhombohedral or trigonal unit cells. Each Ca2+ ion is surrounded by six I– ions and each I– ion is surrounded by 6 Ca2+ ions at the corners of a rhombohedron. The parameter for bond lengths and angle of CaI2 is a = b = c, α = β = γ ≠ 90°.
Is CaI2 soluble in water?
The ability of solute (chemical compound) to dissolve into a solvent (water) at its maximum amount is known as solubility. Take a look at CaI2 solubility in water.
CaI2 is a water-soluble compound. It has 1 metal and 2 non–metals so it can dissolve in water. Iodides of calcium are easily soluble in water. On adding CaI2 to water get ionized as Ca2+ and I– ions. It shows 2 types of water reaction i.e. dissociation reaction and redox reaction.
I– gets oxidized and H+ gets reduced to produce Ca(OH)2 and I with the liberation of H2 gas.
CaI2 (aq) + 2 H2O (l) → Ca(OH)2 (s) + H2 (g) + I2 (s)
How CaI2 is soluble in water?
CaI2 is water soluble because if CaI2 is added to water it undergoes a dissociation reaction and produces Ca(OH)2 with HI. CaI2 get dissociates as Ca2+ and I– ions and is joined to the opposite parts of H2O. Ca2+ joined with OH– ion and I– attached with H+ ions. It forms a hydrogen bond in the solution.
CaI2 + 2 H2O → Ca(OH)2 + 2 HI
Is CaI2 polar or nonpolar?
The electronegativity, geometry with electron distribution, and dipole occurrence tell us about molecules’ polarity. Let us discuss CaI2 polar or non – polar nature.
CaI2 is a non – polar compound. It has a symmetrical arrangement of all Ca and I ions. The CaI2 has a linear geometry and does not have lone pair electrons. The Ca atom is surrounded by two identical atoms i.e. two I atoms. Thus it has equal electron distribution on it and is a non – polar molecule.
Why CaI2 is non – polar?
CaI2 is non – polar because the central Ca atom of the CaI2 molecule is attached to atoms of the same electronegativity i.e. I atoms. Both the atoms have the same electron sharing and the dipoles are created to get to cancel out each other. So, CaI2 has zero dipoles making it a non – polar molecule.
Is CaI2 a molecular compound?
The atoms of a molecule get linked by covalent bonds and consist of small molecules that are molecular compounds. Let us discuss below is CaI2 is molecular or not.
CaI2 compound is not molecular rather it is ionic in nature. The Ca and I atoms in CaI2 is not having any covalent bonds. But its formula is showing the presence of two molecules of iodine atoms like molecular compounds. It is not molecular due to its ionic character and the presence of ionic bonds.
Is CaI2 acid or base?
The compounds or species which donate protons are acids and accept protons are bases. Below is a brief discussion on CaI2‘s acidic or basic nature.
CaI2 is a neutral species and not an acidic and basic compound. In the CaI2 molecule, it has a group 2 cation i.e. Ca2+ is joined with anion I–. These I– anions are the conjugate base of strong acids. Thus on a combination of group 2nd cation and conjugate base anion, it produces neutral compounds.
How CaI2 is a neutral compound?
CaI2 is a neutral molecule because it can produce due to the acid – base reaction. When calcium hydroxide (Ca(OH)2) which is a base get reacts with a hydroiodic acid (HI). There is a formation of CaI2 product which is neutral in nature. The reaction of the formation of CaI2 is given below.
Ca(OH)2 + 2 HI → CaI2 + 2 H2O
Is CaI2 electrolyte?
The compounds which are capable to do ionization in water and can conduct electricity are known as electrolytes. Take a look at the CaI2 electrolytic nature.
CaI2 can show electrolytic nature. Rather it is a strong electrolyte. When CaI2 gets mixed with a water solution, it gets completely ionized as Ca2+ and 2 I– ions. On full dissociation of CaI2 into ions, it can behave as a strong electrolyte in water.
Why CaI2 is a strong electrolyte?
CaI2 is a strong electrolyte because when CaI2 reacts with water dissociation occurs to form Ca2+ and 2I– ions. On application of external electric fields, these ions move freely in the electrolytic solution. Thus it can conduct electricity.
CaI2 → Ca2+ + 2 I–
Is CaI2 salt?
The compounds formed due to the reaction between acids and bases are known as salts. Let us have a brief description of CaI2 salt nature.
CaI2 is a salt that is deliquescent in nature. Salts are generally prepared due to acid-base reactions. It is formed with the reaction of acid and base like calcium hydroxide and hydroiodic acid. Thus there is an occurrence of neutralization reaction and produces a neutral CaI2 compound which is a salt.
Is CaI2 ionic or covalent?
Ionic compounds have a weak bond that breaks into ions and covalent compounds have strong bonds that do not break. Let us discuss whether is CaI2 ionic or covalent.
CaI2 is an ionic compound. It can separate as two different ions. The covalent bond is absent in the CaI2 molecule. Thus the bonds of the CaI2 molecule get easily detached. It has a strong ionic bond is within Ca2+ and 2 I– ions. Thus it is not a covalent compound as it is ionic.
Why CaI2 is ionic?
CaI2 compound is ionic because it consists of 2 opposite charged ions i.e. Ca2+ cation and 2 I– anion. The positive charge and negative charge on Ca2+ and I– occur due to the loss and gain of electrons. Both this ion holds each other with a strong electrostatic force of attraction to form an ionic bond.
Conclusion:
The CaI2 lewis structure contains 16 valence electrons and 6 lone pair electrons. It has a complete octet of both I– ions. It has a formal charge of +2 on the central Ca atom and -1 on both I atoms. It has a linear shape with an 1800 bond angle and sp hybridization. It is a solid salt, ionic, non–polar, and soluble in water. It acts as an electrolyte and is neutral in nature.
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Hello everyone, I am Dr. Shruti M Ramteke, I did my Ph.D. in chemistry. I am passionate about writing and like to share my knowledge with others . Feel free to contact me on linkedin
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