A dative bond is a type of covalent bond where both electrons are provided by one atom.
What is another name for a dative bond?
A dative bond is also known as a coordinate bond.
In a dative bond, how many electrons are provided by the donor atom?
In a dative bond, the donor atom provides both electrons.
In a dative bond, how many electrons are provided by the acceptor atom?
In a dative bond, the acceptor atom provides no electrons for the bond.
What is required for an atom to act as a donor in a dative bond?
The donor atom must have a lone pair of electrons.
What is required for an atom to act as an acceptor in a dative bond?
The acceptor atom must be able to accept a pair of electrons.
What symbol is used to represent a dative bond in a structural formula?
A dative bond is represented by an arrow pointing from the donor to the acceptor atom.
Is a dative bond different from a covalent bond after it is formed?
No, a dative bond is indistinguishable from a normal covalent bond after it is formed.
Name a molecule that can act as an electron donor in dative bond formation.
Ammonia (NH₃) can act as an electron donor.
Name an ion formed by a dative bond.
The ammonium ion (NH₄⁺) is formed by a dative bond.
Name a molecule with a dative bond.
The hydronium ion (H₃O⁺) has a dative bond.
What does electron-deficient mean in the context of dative bonds?
Electron-deficient means the atom does not have enough electrons to achieve a full outer shell.
What kind of molecule is boron trifluoride, BF₃, in relation to dative bonds?
Boron trifluoride (BF₃) is an electron-deficient molecule that can accept a lone pair to form a dative bond.
Does the acceptor atom have to have any lone pairs before forming a dative bond?
No, the acceptor atom does not have to have a lone pair before forming a dative bond.
Does the donor atom have to have any unbonded electrons before forming a dative bond?
Yes, the donor atom must have a lone pair (unbonded pair) of electrons before forming a dative bond.
In the hydronium ion, what molecule acts as the donor?
In the hydronium ion, water (H₂O) acts as the donor.
In the hydronium ion, what ion acts as the acceptor?
In the hydronium ion, the hydrogen ion (H⁺) acts as the acceptor.
In the ammonium ion, what molecule acts as the donor?
In the ammonium ion, ammonia (NH₃) acts as the donor.
In the ammonium ion, what ion acts as the acceptor?
In the ammonium ion, the hydrogen ion (H⁺) acts as the acceptor.
Is the dative bond a type of intermolecular or intramolecular bond?
Dative bonds are considered intramolecular bonds, as they occur within a molecule or ion.
Explanation Questions
Explain why a dative bond is considered a type of covalent bond.
A dative bond is considered a type of covalent bond because it involves the sharing of a pair of electrons between two atoms, just like a regular covalent bond. The key difference is that in a dative bond, both of the shared electrons come from one atom (the donor) rather than each atom contributing one electron.
Describe the formation of the hydronium ion (H₃O⁺) using the concept of dative bonding.
A water molecule (H₂O) has two lone pairs of electrons on the oxygen atom. A hydrogen ion (H⁺), which is electron-deficient, can accept one of these lone pairs from the water molecule. The oxygen atom of the water molecule donates a lone pair of electrons to form a dative bond with the hydrogen ion, resulting in the formation of the hydronium ion (H₃O⁺).
Describe the formation of the ammonium ion (NH₄⁺) using the concept of dative bonding.
An ammonia molecule (NH₃) has one lone pair of electrons on the nitrogen atom. A hydrogen ion (H⁺), which is electron-deficient, can accept this lone pair from the ammonia molecule. The nitrogen atom of the ammonia molecule donates its lone pair to form a dative bond with the hydrogen ion, resulting in the formation of the ammonium ion (NH₄⁺).
Why is it important that a dative bond is indistinguishable from a covalent bond after it is formed?
Once formed, a dative bond becomes identical to a regular covalent bond in terms of strength and properties. This means that after the dative bond is formed, the atoms are held together with equal strength. Therefore, the overall structure of a molecule or ion is determined by the sharing of electrons and not the origin of the electrons.
How does the presence of a lone pair on the donor atom enable the formation of a dative bond?
A lone pair of electrons on the donor atom represents a region of high electron density that can be shared with an electron-deficient atom. This lone pair acts as the source of electrons for the dative bond, enabling the donor atom to form a bond with an acceptor atom that needs additional electrons to achieve stability.
Why is the dative bond represented by an arrow instead of a line?
The arrow in a dative bond represents the direction of electron donation. The arrow points from the donor atom, where the electron pair originates, towards the acceptor atom which receives the electrons. This representation distinguishes dative bonds from normal covalent bonds, where a single line indicates that both atoms contribute one electron each.
Explain the role of electron deficiency in the formation of dative bonds.
An electron-deficient atom lacks sufficient electrons to complete its outer shell. This deficiency creates a need for the atom to accept a pair of electrons. This requirement makes the electron-deficient atom a good candidate for being an acceptor in the formation of dative bonds.
Explain why hydrogen chloride (HCl) does not form dative bonds in water, but forms H₃O⁺ in water.
Hydrogen chloride (HCl) is a strong acid which dissociates readily in water, donating the H⁺. The H⁺ is strongly attracted to the lone pair of electrons on the oxygen atom of the water molecule forming a dative bond, resulting in H₃O⁺. While chlorine has lone pairs, it is not likely to be a donor to hydrogen ions, as hydrogen is more electronegative than chlorine.
Compare and contrast a dative bond with a hydrogen bond.
Both dative and hydrogen bonds involve electrostatic attractions. Dative bonds are a type of covalent bond formed by the sharing of a pair of electrons donated from one atom to another atom. Hydrogen bonds are weaker intermolecular attractions between a partially positive hydrogen and a partially negative atom. Dative bonds form molecules or ions; hydrogen bonds can form between or within molecules.
How can you distinguish between a dative bond and a covalent bond?
Both dative and covalent bonds involve the sharing of electrons between atoms. However, covalent bonds involve atoms sharing one electron each in the formation of a bond. Dative bonds are formed by sharing two electrons where both electrons are donated by one atom.