Draw the Lewis structure for the following: CH3N+H3
The Correct Answer and Explanation is:
Generated code
H H
: :
[ H : C : N : H ]+
: :
H H
IGNORE_WHEN_COPYING_START
IGNORE_WHEN_COPYING_END
Explanation
The provided structure represents the methylammonium cation (CH3NH3+). The process of determining this Lewis structure follows a systematic approach based on chemical principles.
First, we calculate the total number of valence electrons, which are the outermost electrons involved in chemical bonding. Carbon contributes 4, each of the six hydrogens contributes 1 (for a total of 6), and nitrogen contributes 5. The positive charge on the ion indicates that one electron has been lost. Therefore, the total number of valence electrons to be distributed in the structure is 4 + 6 + 5 – 1 = 14 electrons.
Next, the arrangement of the atoms is determined. The chemical formula suggests a central carbon atom bonded to three hydrogen atoms and a nitrogen atom. This nitrogen atom, in turn, is bonded to three additional hydrogen atoms. This creates a skeleton where all atoms are connected by single bonds. There are seven single bonds in total: three between carbon and hydrogen, one between carbon and nitrogen, and three between nitrogen and hydrogen.
Each single bond requires two electrons. With seven bonds, all 14 available valence electrons are used as bonding electrons (7 bonds x 2 electrons/bond = 14 electrons). This means there are no non-bonding electrons, or lone pairs, in this structure.
The final step is to check that the octet rule (for carbon and nitrogen) and the duet rule (for hydrogen) are satisfied and to assign formal charges. Each hydrogen atom shares two electrons, fulfilling the duet rule. The carbon atom is surrounded by four single bonds, giving it a stable octet of eight electrons. The nitrogen atom also has four single bonds, satisfying its octet. The formal charge on the nitrogen atom is calculated to be +1 (5 valence electrons – 0 lone pair electrons – 4 bonding electrons), which accounts for the overall positive charge of the ion. The carbon and hydrogen atoms all have a formal charge of 0.
