Question

What is the formal charge on the nitrogen atom in the ammonium ion (NH4+)? Show the calculation and explain whether the ion is a positive or negative ion based on the formal charge.

Answer 1

To calculate the formal charge on the nitrogen atom in the ammonium ion  NH4+ , we can use the following formula:Formal charge =  Valence electrons of the atom  -  Non-bonding electrons  -  1/2 x Bonding electrons For nitrogen  N , the number of valence electrons is 5. In the ammonium ion, nitrogen is bonded to four hydrogen atoms, and each bond consists of 2 electrons. There are no non-bonding electrons  lone pairs  on the nitrogen atom in this case.Now, let's plug the values into the formula:Formal charge =  5  -  0  -  1/2 x 8 Formal charge = 5 - 0 - 4Formal charge = +1The formal charge on the nitrogen atom in the ammonium ion  NH4+  is +1. Since the formal charge is positive, the ion is a positive ion  cation .