Test: Chemical Bonding- 1

LiF (Lithium Fluoride) is an example of Ionic bond, as the formation takes place by transfer of electrons and not by sharing.

Lateral overlap along the X-axis between two d_zx orbitals leads to the formation of a Pi-bond.

Magnesium Oxide(MgO) is used to make linings for some furnaces. It is known as a refractory material - which just means that it is resistant to heat and retains its strength at very high temperatures.

This is because they have the tendency to transfer electrons.

Both Ionic and Covalent bond arise from the tendency of atoms to attain stable configuration of electrons.

• As we know that ionic bond is formed between an electropositive and an electronegative atom and a covalent bond is formed between two electronegative or electropositive elements.
• In all the above options NO₃ the bonds are ionic in nature but NO3 is covalent in nature as bond is formed between two electronegative atoms i.e. N and O.

Ammonia adopts sp³ hybridization (HNH bond angle 108°) whereas the other members of the XH₃ series PH₃, AsH₃, SbH₃, and BiH₃ instead prefer octahedral bond angles of 90-93°. 

• Carbonium ion methonium,  CH₅+ is produced by the addition of  H+ to CH₄. In CH₅+ three hydrogen atoms are in a plane and one above and one below the plane. 
  
• So its sp³d and the shape is trigonal bipyramid. 
• But this compound is considered a CH₃+ carbenium ion with a molecule of hydrogen interacting with the empty orbital in a
  3-center-2-electron bond.
• As the two hydrogen atoms in H2 are in continuously exchange positions with the three hydrogen atoms in the CH₃+ methonium CH₅+ is considered as a fluxional molecule. Due to the existence of CH₃+, this is sp²​ hybridised. 

Both Ionic and Covalent bond arise from the tendency of atoms to attain stable configuration of electrons.

In pyrolle there is greater resonance effect n due to more electronegativity in furan more inductive effect pronounced so the direction of dipole moment in furan is towards oxygen.

In chemistry, phi bonds (φ bonds) are covalent chemical bonds, where six lobes of one involved atomic orbital overlap six lobes of the other involved atomic orbital.

The percentage of p-character in forming P-P bonds in P₄ molecule is: 0. In forming 
P₄ molecule, P atom uses sp³ hybrid orbitals. Thus, the p-character in hybrid orbitals is 75%.

Due to the presence of lone pair on H₂Se and also less electronegative than oxygen and sulphur that's why hybridization decreases and S character increases.

When BF₃ forms an adduct with ether, it has 4 bonds respectively bonded with Oxygen (of ether) nd 3 F atoms. Presence of 4 bonds to the central atom results in sp³ hybridization.

H = 1/2 [V+M−C+A]
where,
H = Number of orbitals involved in hybridization.
V = Valence electrons of the central atom.
M = Number of monovalent atoms linked to the central atom.
C = Charge of the cation.
A = Charge of the anion.

NH₂^-

H = 1/2[5+2+1] 
= 4.
⇒ sp³ hybridized state.
The hybridization of NH^-- is also sp³

Ionic bond results from a), b) and d). But the transfer of electrons is a property of Covalent bond.

An allene is a compound in which one carbon atom has double bonds with each of its two adjacent carbon centres.

The central carbon atom of allene forms two sigma bonds and two pi bonds. The central carbon is sp-hybridized, and the two terminal carbon atoms are sp²-hybridized. The bond angle formed by the three carbon atoms is 180°, indicating linear geometry for the carbon atoms of allene.

According to Drago's rule when the following conditions are satisfied, then the energy difference between the participating atomic orbitals will be very high and thus no mixing of orbitals or hybridization takes place.

• At least one lone pair must be present on the central atom.
• The central atom must be of 2nd period.
• The electronegativity of the surrounding atom must be less than or equal to 2.1.
• No hybridisation means bonding will take place through pure atomic p orbitals as in SbH₃ and thus bond angle will be approximately equal to 90⁰.

A hypervalent molecule (the phenomenon is sometimes colloquially known as expanded octet) is a molecule that contains one or more main group elements apparently bearing more than eight electrons in their valence shells.