Boron trifluoride (BF3) and ammonia (NH3) react to form a complex which involves the formation of a coordinate covalent bond. The reaction can be represented using Lewis electron dot structures.
1. **Lewis Structure of BF3:** In BF3, boron has three single bonds with three fluorine atoms. Since boron has only six electrons in its valence shell, it is electron-deficient.
2. **Lewis Structure of NH3:** Ammonia has a nitrogen atom bonded to three hydrogen atoms, and it possesses a lone pair of electrons. The nitrogen has a complete octet.
3. **Formation of the Coordinate Covalent Bond:** During the reaction, the lone pair of electrons from the nitrogen atom in ammonia is donated to the empty p-orbital of the boron atom in BF3. This results in the formation of a coordinate covalent bond.
4. **The Reaction Equation:** The overall reaction can be represented as:
BF3 + NH3 → BF3•NH3
The resulting complex (BF3•NH3) now has a stable arrangement where boron is benefitting from the additional pair of electrons, thus achieving a more stable state.