Nitrogen dioxide, NO2, can undergo reactions to form nitrite ion, NO2–, and nitronium ion, NO2+. — Chemical Bonding / Molecular Structure Chemistry Question
Problem Context
Nitrogen dioxide, NO2, can undergo reactions to form nitrite ion, NO2–, and nitronium ion, NO2+.
Draw Lewis structures for NO2– and NO2+ including any resonance forms.
Model Answer
For NO2– and for NO2+
Predict the shape of each ion and account for each shape using a modern bonding theory.
Model Answer
NO2– will be bent due to the lone pair of electrons on N. NO2+ will be linear.
Describe and account for the difference in the N–O bond lengths in NO2– and NO2+.
Model Answer
Nitrogen-to-oxygen bonds in NO2– will be longer than those in NO2+. The average bond order in NO2– is 11/2. The bond order in NO2+ is 2.
Determine the oxidation number and the formal charge of nitrogen in the NO2– ion. Outline your reasoning and state the difference between formal charge and oxidation number.
Model Answer
The oxidation number of N in NO2– is +3. Formal charge is zero. The oxidation number is obtained by assigning bonding electrons to the more electronegative atom. The formal charge is found by dividing the bonding electrons evenly between atoms. The number of electrons left is compared with the original number.