Question

Explain acidic nature of co2 on basis of lewis theory

Answer 1

I hope you can see how  

CO

2

COX2

is a Lewis acid because it is able to accept electrons. Although in the principal resonance structure you see all atoms have full octets of electrons, the double bonds can easily break, rearranging the electrons. If full octets prevented atoms from receiving electrons, a great percentage of all known reactions would not occur. The key is that the electrons in the octet must have an alternative place to go if new electrons are donated to the molecule (in this case, the electrons migrate to the  

O

O

atom). In more advanced chemistry, we would say  

O

O

acted as an electron sink in this process.