The formamidinium ion structure is shown below.
Answer:
A: trigonal planar
B: trigonal pyramidal
Step-by-step explanation:
In the formamidinium ion, there are two nitrogen atoms, which are represented below by A and B. The geometry of a molecule is determined by the VSEPR theory, which states that the bonded electrons and the lone pairs of electrons intended to repulse to form a more stable compound.
Nitrogen has 5 electrons in its valence shell, so n the nitrogen A, there are 3 bonds (1 double bond and 2 simple bonds), and there are no lone pairs in the nitrogen atom (the central atom), thus the repulsive forces will be only by the bonds, and the geometry will be trigonal planar.
In nitrogen B, there are 3 simple bonds and one lone pair, which contributes to the repulsive forces, thus, the geometry must be trigonal pyramidal.