Question

draw lewis structure for, cho₂⁻

Explanation:

Step1: Calculate valence electrons

Carbon has 4 valence electrons, hydrogen has 1, each oxygen has 6, and there is an extra electron due to the - 1 charge. So total valence electrons = 4 + 1+2×6 + 1=18.

Step2: Determine the central atom

Carbon is the central atom as it is less electronegative than oxygen.

Step3: Connect atoms with single - bonds

Connect carbon to hydrogen with a single - bond and carbon to each oxygen with a single - bond. This uses 4 electrons (2 for C - H and 2 for each C - O), leaving 18 - 4 = 14 electrons.

Step4: Distribute remaining electrons as lone - pairs

Distribute the remaining 14 electrons as lone - pairs on the oxygen atoms to satisfy the octet rule. One oxygen will have 3 lone - pairs and the other will have 2 lone - pairs. But this gives a formal charge on carbon.

Step5: Form a double - bond

To reduce the formal charge, move one lone - pair from the oxygen with 2 lone - pairs to form a C = O double - bond.

The Lewis structure has a carbon atom in the center bonded to a hydrogen atom by a single - bond, and to one oxygen atom by a single - bond and to the other oxygen atom by a double - bond. The oxygen with the single - bond has 3 lone - pairs and a negative charge, and the oxygen with the double - bond has 2 lone - pairs.

Answer:

The Lewis structure of $CHO_2^-$ has a central carbon bonded to a hydrogen by a single - bond, to one oxygen by a single - bond (with 3 lone - pairs and a negative charge) and to another oxygen by a double - bond (with 2 lone - pairs).