Co-ordinate or Dative bonding Questions in English

(C) The structure of nitric acid $(HNO_3)$ involves one $N=O$ bond,one $N-OH$ bond,and one coordinate covalent bond (dative bond) from $N$ to $O$.
Nitrogen forms a total of $4$ covalent bonds (one double bond,one single bond,and one coordinate bond).
Therefore,the covalency of nitrogen in $HNO_3$ is $4$.

(B) coordinate covalent bond (or dative bond) is formed when one atom provides both electrons for the shared pair.
In $H_2SO_4$,the sulfur atom is bonded to two hydroxyl groups by covalent bonds and to two oxygen atoms by coordinate covalent bonds (where $S$ donates a lone pair to each $O$ atom).
Thus,$H_2SO_4$ contains coordinate covalent bonds.

(C) $NH_3$ has a lone pair of electrons,while $BF_3$ is an electron-deficient compound.
Therefore,they form a coordinate (dative) bond by sharing the lone pair from nitrogen to boron.
The reaction is represented as: $NH_3 \to BF_3$.

(D) $HNO_2$ (nitrous acid) does not contain a coordinate bond.
The structure of $HNO_2$ is $H-O-N=O$,where all bonds are covalent.
In contrast,$SO_2$ $(O=S \leftarrow O)$,$HNO_3$ $(H-O-N(=O) \leftarrow O)$,and $H_2SO_3$ ($H-O-S(=O)-O-H$ with a coordinate bond from $S$ to $O$) all contain coordinate bonds.

(B) coordinate covalent bond (also known as a dative bond) is a type of covalent bond in which both electrons of the shared pair come from the same atom.
Unlike a normal covalent bond where each atom contributes one electron to the shared pair,in a coordinate bond,one atom acts as a donor (providing the electron pair) and the other acts as an acceptor.
Therefore,it is formed by the sharing of an electron pair donated by a single atom.

(B) In a coordinate bond (also known as a dative bond),the $2$ electrons forming the bond are provided by only one of the two participating atoms.
This shared pair of electrons is donated by one atom to another,resulting in the formation of a coordinate covalent bond.

(A) The correct answer is $A$.
In $N_2O_5$,the structure involves two nitrogen atoms connected by an oxygen atom $(N-O-N)$.
Each nitrogen atom is also bonded to one terminal oxygen atom via a double bond and to another terminal oxygen atom via a coordinate covalent bond (dative bond).
Thus,$N_2O_5$ contains coordinate covalent bonds.

(D) coordinate or dative bond is a type of covalent bond in which both electrons of the shared pair are contributed by only one of the two participating atoms.
For the formation of a coordinate bond,the donor atom must possess at least one lone pair of electrons (an unshared electron pair) to donate to the acceptor atom.

(A) In the sulfite ion $(SO_3^{2-})$,the sulfur atom is bonded to three oxygen atoms.
To satisfy the octet rule for all atoms,one of the $S-O$ bonds is represented as a coordinate covalent bond (dative bond) where the sulfur atom donates a lone pair of electrons to an oxygen atom.
In contrast,$CH_4$,$CO_2$,and $NH_3$ primarily involve covalent bonds formed by electron sharing without coordinate bonds in their standard Lewis structures.

(D) coordinate bond (or dative bond) is a type of covalent bond where both electrons of the shared pair are contributed by only one of the two participating atoms.
In $O_3$ (ozone),the central oxygen atom forms a coordinate bond with the terminal oxygen atom.
In $SO_3$ (sulfur trioxide),the sulfur atom forms coordinate bonds with two oxygen atoms.
In $H_2SO_4$ (sulfuric acid),the sulfur atom forms coordinate bonds with two oxygen atoms.
Since all these molecules contain at least one coordinate bond,the correct option is $D$.

(C) The structure of sulphuric acid $(H_2SO_4)$ consists of a central sulphur atom bonded to two hydroxyl groups $(-OH)$ via single covalent bonds and two oxygen atoms via double covalent bonds.
In the Lewis structure,all bonds are covalent. While older representations sometimes depicted two $S \rightarrow O$ coordinate (dative) bonds,modern valence bond theory and formal charge calculations show that these are best represented as $S=O$ double bonds.
Therefore,the number of dative bonds in a sulphuric acid molecule is $0$.

(A) In $CH_3NC$ (methyl isocyanide),the nitrogen atom donates a lone pair of electrons to the carbon atom to form a coordinate (dative) bond. The structure is $CH_3-N \rightarrow C$. Therefore,the correct option is $A$.

(B) Since $BH_3$ is a Lewis acid,it acts as an electron pair acceptor.
$(C_2H_5)_2O$ (diethyl ether) acts as a Lewis base because the oxygen atom has lone pairs of electrons.
The oxygen atom donates a lone pair of electrons to the boron atom in $BH_3$.
Therefore,the bond formed between $B$ and $O$ is a co-ordinate covalent bond (also known as a dative bond).

(A) coordinate covalent bond (or dative bond) is formed when one atom donates a lone pair of electrons to another atom that needs them to complete its octet.
In the reaction $H_2O + H^{+} \to H_3O^{+}$,the oxygen atom in water has two lone pairs of electrons.
It donates one of these lone pairs to the $H^{+}$ ion,which has an empty $1s$ orbital.
This results in the formation of a hydronium ion $(H_3O^{+})$,where the bond between $O$ and $H^{+}$ is a coordinate covalent bond.
Therefore,the correct option is $A$.

(B) Lewis base is defined as a species that can donate a lone pair of electrons to form a coordinate covalent bond.
In the reaction $I_2 + I^{-} \to I_3^-$,the iodide ion $(I^{-})$ acts as the electron pair donor.
Therefore,$I^{-}$ is the Lewis base.

(D) According to the Lewis theory,an acid is an electron pair acceptor and a base is an electron pair donor.
Neutralization in this theory is defined as the formation of a coordinate covalent bond (also known as a dative bond) between the Lewis acid and the Lewis base,resulting in the formation of an adduct.

(B) Lewis base is defined as a substance that can donate an electron pair.
In the reaction $BCl_3 + PH_3 \rightarrow Cl_3B^{-}PH_3$,the phosphorus atom in $PH_3$ has a lone pair of electrons.
$PH_3$ donates this lone pair to the electron-deficient boron atom in $BCl_3$ to form a coordinate covalent bond.
Therefore,$PH_3$ acts as the Lewis base.

(A) In the reaction $NH_3 + BF_3 \rightleftharpoons NH_3 \to BF_3$,the $NH_3$ molecule has a lone pair of electrons on the nitrogen atom,which it donates to the $BF_3$ molecule.
$BF_3$ acts as an electron pair acceptor because the boron atom has an incomplete octet.
According to the Lewis concept,a substance that accepts an electron pair is a Lewis acid.
Therefore,$BF_3$ is a Lewis acid.

(D) Lewis base is defined as a substance that can donate a lone pair of electrons.
In $NH_3$,the nitrogen atom has one lone pair of electrons,which it can donate to an electron-deficient species.
Therefore,$NH_3$ acts as a Lewis base.

(D) Both $H_2$ and $Cl_2$ are non-polar covalent molecules.
$Cl_2$ contains lone pairs of electrons on the chlorine atoms,which can be donated to form a coordinate bond (e.g.,in complexes).
$H_2$ does not have any lone pairs of electrons to donate.
Therefore,the correct difference is that the hydrogen molecule cannot participate in coordination bond formation,while the chlorine molecule can.

(B) dative bond (coordinate covalent bond) is formed when a species with a lone pair of electrons donates them to an electron-deficient species.
Ammonia $(NH_3)$ acts as a Lewis base because it has a lone pair of electrons on the nitrogen atom.
$BCl_3$ is a Lewis acid because the boron atom has an incomplete octet (only $6$ electrons in its valence shell).
Therefore,$NH_3$ donates its lone pair to the boron atom in $BCl_3$ to form an adduct,$H_3N \rightarrow BCl_3$,which contains a dative bond.

(D) The heat of dissociation of an adduct $(CH_3)_3N \to BX_3$ depends on the strength of the Lewis acid $BX_3$.
As the number of electron-donating methyl groups $(-CH_3)$ on the boron atom increases,the Lewis acidity of the boron compound decreases due to the $+I$ effect.
The order of Lewis acidity is $BF_3 > B(CH_3)F_2 > B(CH_3)_2F > B(CH_3)_3$.
Since $B(CH_3)_3$ is the weakest Lewis acid among the given options,the adduct $(CH_3)_3N \to B(CH_3)_3$ has the weakest $N-B$ bond and therefore the minimum heat of dissociation.

(D) The cyanide ion $(CN^-)$ contains a lone pair of electrons on the carbon atom.
Because it has an electron-rich site capable of donating an electron pair to an electrophile,it acts as a nucleophilic centre.
Therefore,the correct option is $D$.

(D) In $AlCl_3$,the $Al$ atom is electron-deficient,having only $6$ electrons in its valence shell.
To complete its octet,$AlCl_3$ forms a dimer $Al_2Cl_6$ by sharing lone pairs of electrons from the chlorine atoms of another $AlCl_3$ molecule,resulting in coordinate bonds.
This is due to the incomplete octet or electron-deficient nature of the $Al$ atom.

(B) Lewis acid is defined as an electron pair acceptor.
In the reaction $SnCl_2 + 2Cl^{-} \rightarrow [SnCl_4]^{2-}$,the $SnCl_2$ molecule accepts electron pairs from the chloride ions $(Cl^{-})$.
Since $SnCl_2$ accepts electron pairs to form the complex ion $[SnCl_4]^{2-}$,it acts as a Lewis acid.
Therefore,the correct option is $B$.

(A) Lewis base is defined as a species that can donate a lone pair of electrons.
In the reaction $I_2 + I^{-} \rightarrow I_3^-$,the iodide ion $(I^{-})$ has a lone pair of electrons which it donates to the iodine molecule $(I_2)$ to form the triiodide ion $(I_3^-)$.
Therefore,$I^{-}$ acts as the Lewis base and $I_2$ acts as the Lewis acid.

(A) Lewis base is defined as a species that can donate a lone pair of electrons.
In the given reaction,$PH_3$ has a lone pair of electrons on the phosphorus atom,which it donates to the electron-deficient boron atom in $BCl_3$.
Therefore,$PH_3$ acts as a Lewis base,and $BCl_3$ acts as a Lewis acid.

(C) The structure of $H_2SO_4$ is $H-O-S(=O)_2-O-H$.
In this structure,the $S-O$ bonds formed by sharing electrons are covalent,and the two $S=O$ bonds are coordinate covalent bonds (dative bonds) where sulfur donates a lone pair to oxygen.
Thus,the molecule contains both covalent and coordinate covalent bonds.

(B) coordinate covalent bond is formed between the lone pair of nitrogen in hydrazine $(N_2H_4)$ and a proton $(H^+)$ to form the hydrazinium ion $(N_2H_5^+)$.
In $N_2H_5^+$,one nitrogen atom donates its lone pair to the $H^+$ ion,establishing a coordinate bond.

(C) In $BH_4^-$,the $BH_3$ molecule accepts a hydride ion $(H^-)$ to form a coordinate bond between $B$ and $H$.
In $NH_4^+$,the $NH_3$ molecule accepts an $H^+$ ion,forming a coordinate bond between $N$ and $H$.
In $H_3O^+$,the $H_2O$ molecule accepts an $H^+$ ion,forming a coordinate bond between $O$ and $H$.
In $CO_3^{2-}$,the structure consists of one $C=O$ double bond and two $C-O$ single bonds with negative charges on the oxygen atoms. It does not contain a coordinate covalent bond.

(B) Ferric chloride $(FeCl_3)$ exists as a dimer,$Fe_2Cl_6$,in the vapor phase or in non-polar solvents to satisfy the octet of the iron atom through coordinate bonding.

(A) $NH_4Cl$ contains a coordinate covalent bond.
In the ammonium ion $(NH_4^+)$,the nitrogen atom donates its lone pair of electrons to the $H^+$ ion to form a coordinate bond.
The structure is represented as $[H_3N \to H]^+ Cl^-$,where the arrow indicates the coordinate bond.

(B) The co-ordinate bond (dative bond) is a type of covalent bond where both electrons come from one atom.
In $BH_4^-$,the $B-H$ bond formed by the reaction of $BH_3$ and $H^-$ is a co-ordinate bond.
In $H_3O^{+}$,the $O-H$ bond formed by the reaction of $H_2O$ and $H^{+}$ is a co-ordinate bond.
In $NH_4^{+}$,the $N-H$ bond formed by the reaction of $NH_3$ and $H^{+}$ is a co-ordinate bond.
In $CO_3^{2-}$,the structure consists of one $C=O$ double bond and two $C-O$ single bonds with formal charges on oxygen atoms. There is no dative bond involved in its resonance structures.
Therefore,the correct option is $B$.

(B) Lewis base is a substance that can donate a lone pair of electrons.
$1$. $BF_3$: Boron has an incomplete octet ($6$ electrons),making it a Lewis acid.
$2$. $PF_3$: Phosphorus has $5$ valence electrons,$3$ are used in bonding with $F$ atoms,leaving one lone pair on the $P$ atom. This lone pair can be donated,making $PF_3$ a Lewis base.
$3$. $CF_4$: Carbon has a complete octet and no lone pairs,making it chemically inert in this context.
$4$. $SiF_4$: Silicon has empty $d$-orbitals,allowing it to accept electron pairs,making it a Lewis acid.
Therefore,$PF_3$ is the correct answer.

(D) In the crystal structure of $CuSO_4 \cdot 5H_2O$,the $Cu^{2+}$ ion is coordinated to four water molecules through coordinate bonds,forming a square planar geometry $[Cu(H_2O)_4]^{2+}$.
The fifth water molecule is held by hydrogen bonding between the $SO_4^{2-}$ ion and the coordinated water molecules.
Therefore,the copper ion forms $4$ coordinate bonds with water.

(B) The chemical formula $(NH_4)_3PO_4$ consists of $3$ ammonium ions $(NH_4^+)$ and $1$ phosphate ion $(PO_4^{3-})$.
In each $NH_4^+$ ion,there is $1$ coordinate bond formed between the lone pair of nitrogen and the $H^+$ ion.
Since there are $3$ ammonium ions in one molecule of $(NH_4)_3PO_4$,the total number of coordinate bonds is $3 \times 1 = 3$.

(A) dative bond (also known as a coordinate covalent bond) is a covalent bond in which both electrons come from the same atom.
In $O_3$ (ozone),the central oxygen atom forms a double bond with one oxygen atom and a coordinate covalent bond (dative bond) with the other oxygen atom to complete its octet.
$NH_3$ contains only polar covalent bonds.
$BaCl_2$ is an ionic compound.
$BI_3$ contains covalent bonds where boron is electron-deficient.

(C) In the reaction $BF_3 + NH_3 \to F_3B.NH_3$,$BF_3$ is a Lewis acid with $sp^2$ hybridization and trigonal planar geometry.
$NH_3$ is a Lewis base with $sp^3$ hybridization and pyramidal geometry.
When they react,$B$ atom in $BF_3$ changes its hybridization from $sp^2$ to $sp^3$ to form a coordinate bond with $N$ atom.
Consequently,the geometry of $BF_3$ changes from trigonal planar to tetrahedral.
Therefore,the regular geometry of $BF_3$ is changed.

(A) $AlCl_3$ is a Lewis acid because it has an incomplete octet and can accept a lone pair of electrons. $CH_3OCH_3$ (dimethyl ether) is a Lewis base because the oxygen atom has two lone pairs of electrons. The reaction involves the donation of a lone pair from the oxygen atom of the ether to the aluminum atom of $AlCl_3$,forming a coordinate covalent bond (Lewis acid-base adduct). The oxygen atom acquires a positive charge,and the aluminum atom acquires a negative charge. The product is $(CH_3)_2O^{+} - Al^{-}Cl_3$.

(D) dative bond (coordinate covalent bond) is not involved in the dimerisation of benzoic acid.
In the dimerisation of benzoic acid,two molecules are held together by intermolecular $H$-bonding.
In the protonation of ether $(R-O-R + H^+ \rightarrow R-O^+(H)-R)$,a dative bond exists between the oxygen atom of the ether and the $H^+$ ion.
When $HCl$ dissolves in water,it forms $H_3O^+$,which contains a dative bond between the oxygen of water and the $H^+$ ion.
In the dimerisation of $BeCl_2$,dative bonds are formed by the donation of lone pairs from chlorine atoms of one $BeCl_2$ molecule to the electron-deficient $Be$ atom of another $BeCl_2$ molecule.

(A) dative bond,also known as a coordinate covalent bond,is formed when one atom provides both electrons for the shared pair.
In the ozone molecule $(O_3)$,the central oxygen atom forms a double bond with one oxygen atom and a coordinate (dative) bond with the other oxygen atom to complete its octet.
$NH_3$ contains only covalent bonds.
$BaCl_2$ is an ionic compound.
$BI_3$ contains covalent bonds where boron is electron-deficient.

(C) The structure of $N_2O_5$ consists of two nitrogen atoms bonded to a central oxygen atom $(N-O-N)$.
Each nitrogen atom is also double-bonded to an oxygen atom and forms a coordinate covalent bond with another oxygen atom.
Since nitrogen and oxygen are both non-metals,the bonds formed are covalent and coordinate covalent in nature.
There are no ionic bonds present in $N_2O_5$.

(D) coordinate bond (or dative bond) is a type of covalent bond where both electrons come from the same atom.
$1$. In $PH_4^+$,the $P$ atom donates a lone pair to an $H^+$ ion,forming a coordinate bond.
$2$. In $NO_2$,the nitrogen atom forms a coordinate bond with one of the oxygen atoms to complete its octet.
$3$. In $O_3$ (ozone),one oxygen atom forms a coordinate bond with another oxygen atom.
$4$. In $CO_3^{2-}$,the structure consists of one $C=O$ double bond and two $C-O$ single bonds with resonance,involving only standard covalent bonds. There is no coordinate bond present.
Therefore,the correct option is $D$.

(A) coordinate covalent bond (also known as a dative bond) is formed when one atom donates a pair of electrons to another atom that needs them to complete its octet.
In the case of $N_2H_5^+$,it is formed by the protonation of hydrazine $(N_2H_4)$.
The nitrogen atom in $N_2H_4$ has a lone pair of electrons.
When $H^+$ approaches,the nitrogen atom donates its lone pair to the $H^+$ ion,forming a coordinate covalent bond $(N \rightarrow H^+)$.
Therefore,$N_2H_5^+$ contains a coordinate covalent bond.

(C) Both $NH_3$ and $PH_3$ act as Lewis bases due to the presence of a lone pair of electrons on the central atom ($N$ and $P$ respectively).
Therefore,they both exhibit basic character.

(B) The structure of $N_2O_5$ is $O_2N-O-NO_2$.
In this molecule,the $N-O$ bonds are covalent,and the $N \rightarrow O$ bonds are coordinate covalent bonds.
Therefore,$N_2O_5$ contains both covalent and coordinate bonds.

(D) coordinate covalent bond (also known as a dative bond) is a type of covalent bond where both electrons come from the same atom.
$1$. In ozone $(O_3)$,the central oxygen atom forms a double bond with one oxygen atom and a coordinate bond with the other.
$2$. In sulfur trioxide $(SO_3)$,the sulfur atom forms one double bond and two coordinate bonds with oxygen atoms.
$3$. In sulfuric acid $(H_2SO_4)$,the sulfur atom forms two double bonds with oxygen atoms and two single bonds with hydroxyl groups (or,in some representations,two coordinate bonds and two single bonds to oxygen atoms).
Since all these molecules contain coordinate covalent bonds,the correct answer is $D$.

(C) The chemical formula of sulfuric acid is $H_2SO_4$.
In the structure of $H_2SO_4$,the central sulfur atom is bonded to two hydroxyl $(-OH)$ groups via single covalent bonds and to two oxygen atoms via double bonds.
However,in terms of coordinate (dative) bonding,the two oxygen atoms are linked to the sulfur atom by dative bonds (often represented as $S \rightarrow O$).
Therefore,there are $2$ dative bonds in a sulfuric acid molecule.

(B) In $(SiH_3)_3N$,the nitrogen atom has a lone pair of electrons.
Silicon has vacant $3d$ orbitals.
The lone pair on nitrogen is donated into the vacant $d$ orbital of silicon,forming a $p\pi-d\pi$ back bond.
Due to this back bonding,the nitrogen atom undergoes $sp^2$ hybridization and adopts a planar geometry.

(C) coordinate covalent bond (dative bond) is formed when one atom donates a lone pair of electrons to another atom.
In $BH_4^-$,the $BH_3$ molecule accepts a hydride ion $(H^-)$ to form the bond,which is a coordinate bond.
In $NH_4^+$,the lone pair on nitrogen in $NH_3$ is donated to an $H^+$ ion,forming a coordinate bond.
In $H_3O^+$,the lone pair on oxygen in $H_2O$ is donated to an $H^+$ ion,forming a coordinate bond.
In $CO_3^{2-}$,the structure consists of one $C=O$ double bond and two $C-O$ single bonds with formal charges on oxygen atoms. All bonds are covalent,and there is no dative (coordinate) bond involved in the standard Lewis structure representation.