Which of the following compound is the limitation of Lewis octet rule? CCl4 CO2 NO NH3

The compound that is the limitation of the Lewis octet rule among the given options is NO (Nitric Oxide).

Here's why:

1. CCl4 (Carbon Tetrachloride): Each Chlorine atom shares one electron with Carbon to complete its octet and Carbon shares one electron with each Chlorine atom to complete its octet. So, Lewis octet rule is obeyed.

2. CO2 (Carbon Dioxide): Each Oxygen atom shares two electrons with Carbon to complete its octet and Carbon shares two electrons with each Oxygen atom to complete its octet. So, Lewis octet rule is obeyed.

3. NO (Nitric Oxide): Nitrogen shares two electrons with Oxygen and Oxygen shares one electron with Nitrogen. Nitrogen has 5 valence electrons and Oxygen has 6. After sharing, Nitrogen has 8 electrons (completing its octet) but Oxygen has only 7 electrons (not completing its octet). So, Lewis octet rule is not obeyed.

4. NH3 (Ammonia): Each Hydrogen atom shares one electron with Nitrogen to complete its duplet and Nitrogen shares one electron with each Hydrogen atom to complete its octet. So, Lewis octet rule is obeyed.

Therefore, NO is the compound that is the limitation of the Lewis octet rule.