`BF_3` and `NH_3` combine readily because of the formation of

Options

A. a dative bond
B. an ionic bond
C. a hydrogen bond
D. a covalent bond

Answer

A

Explanation

Although boron trifluoride `(BF_3)` is stable, it has a tendency to pick up an unshared electron pair from an atom in another compound, as shown by its reaction with ammonia:
`F-underset(F)underset(|)overset(F)overset(|)B+:underset(H)underset(|)overset(H)overset(|)NrarrF-underset(F)underset(|)overset(F)overset(|)(B^(-))-^(+)N-H`
The formation of this compound satisfies the octet rule for B, N, and F atoms. The `B-N` bond in the above compound is a dative bond because both electrons for sharing are contributed by the N atom.