A bond formed by sharing a pair of electrons provided, both electrons are by one of the two bonded atoms is called a dative bond or a coordinate covalent bond. The atom providing two electrons to form a dative bond is called a donor and the atom sharing the pair of electrons from a donor is known as an acceptor. A dative bond may be represented with an arrow from the donor to the acceptor as A–> B with a positive charge on the donor and negative charge on the acceptor. The donor should have at least one lone pair of electrons and acceptor should have a vacant orbital. Coordinate covalent compounds are nonelectrolytes that do not conduct electricity because they do not ionise in water.
1. When two species A and B form an electron-pair bond and A does not provide its electrons for bonding, the bond present between A and B must be
2. Each of the following pairs of chemical species will combine. Which of the following combinations is best explained by the coordinate covalent bond?
- H2 + I2
- Mg +O2
- Cl + Cl
- H+ + H2O
3. BF3 forms an adduct with NH3 because
- nitrogen has a high electronegativity
- boron has a high electronegativity
- boron has an empty p-orbital and nitrogen has one lone pair of electrons
- boron has an electropositive character
4. Protons play an important role in which type of bonding?
5. Which of the following compounds contain all three types: ionic, covalent and dative bonds?
- Solid N2O5
6. The type of bond formed during the hydration of cation is
- dative bond
7. Which of the following compounds has electrovalent linkage?
8. Which of the following bonds has the most polar character?
9. A molecule with multiple covalent bonds is
10. The weakest bond is
- Van der Waals