Exams › JEE Main › Chemistry

Which of the following statements is correct regarding the carboxylate-type anions acetate (CH3COO-) and formate (HCOO-)?

1. The two carbon-oxygen bonds are equal in length in the acetate ion
2. The resonance (canonical) structures of the acetate ion are non-equivalent
3. The two carbon-oxygen bonds are unequal in length in the formate ion
4. The resonance structures of the formate ion are non-equivalent

Correct answer: The two carbon-oxygen bonds are equal in length in the acetate ion

Solution

Both acetate and formate ions are stabilized by two equivalent resonance structures in which the negative charge is delocalized equally over the two oxygen atoms. As a result, the two carbon-oxygen bonds in each ion are identical in length (intermediate between a single and double bond). Therefore the correct statement is that the two C-O bonds in acetate are equal in length. (The statement that formate's C-O bonds are unequal, and that the resonance structures are non-equivalent, are both false.)

Related JEE Main Chemistry questions

• Although the electronegativity gap between N and F is larger than that between N and H, ammonia has a dipole moment of 1.5 D while nitrogen trifluoride has only 0.2 D. The reason is that
• When N₂ is converted into N₂⁺, the dissociation energy of the N–N bond ______, and when O₂ is converted into O₂⁺, the dissociation energy of the O–O bond ______.
• From the ions listed below, which pair has geometries that can be accounted for by the same type of orbital hybridization? NO₂⁻, NO₃⁻, NH₂⁻, NH₄⁺, SCN⁻
• Atoms A and B have electronegativities of 1.20 and 4.0, respectively. What is the percentage ionic character of the A–B bond?
• In the phosphate ion, PO₄³⁻, what is the formal charge on an oxygen atom that is singly bonded to phosphorus in a P–O bond?
• Among the following species, which one has no unpaired electrons?

⚔️ Practice JEE Main Chemistry free + battle 1v1 →