Sabtu, 15 Ogos 2015

Most Plausible Cyanate ion NCO-

Let us consider the case of cyanate ion NCO-



Step 1: Draw skeletal structure
The central atom will be the C atom since it is the less electronegative.
Connect the atoms with single bonds.


Step 2: Calculate the valence electron

Carbon: 4e  x 1   = 4e
Oxygen: 6e x 1   = 6e
Nitrogen: 5e x 1 = 5e
charge -1            = 1e
Total                  = 16e


Step 3: Complete the octet.
Complete the surrounding atom then, the central atom.
The carbon do not have enough electron. So, move the lone pair electron to become bonding pair electron. 


Step 4: Considering formal charge, identify the most plausible structure






So, the 1st structure is the most plausible structure. This is because negative formal charge at the most electronegative atom (oxygen).


Now, try to identify most plausible Lewis structure for NCS-