Methanoic acid HCOOH has one carbon-oxygen bond of length 123 PM and another of 136 PM. The C = O and C-O bond lengths respectively would be:

Explanation

The correct answer is 123 PM for the C = O bond and 136 PM for the C-O bond. In organic chemistry, the C = O bond is typically a double bond and therefore shorter due to the increased overlap of the orbitals, which leads to a bond length around 123 PM. On the other hand, the C-O bond is usually a single bond, resulting in a longer bond length of about 136 PM. This is consistent with the typical structures observed in carboxylic acids like methanoic acid. Option A is incorrect because it reverses these lengths. Option C is incorrect because it suggests both bonds are 136 PM, which is not typical for methanoic acid. Option D suggests both bonds are 123 PM, which is also incorrect as it implies both bonds are double bonds, which is not possible in this molecule.