Chemistry Chemical Bonding SET 2019
PMDC Verified Question 74 of 102
Among the following molecules, which one has coordinate covalent (dative) bond?
A
\( \text{CCl}_4 \)
B
\( \text{CO} \)
C
\( \text{CO}_2 \)
D
\( \text{CH}_4 \)
Tap any option to test your recall and reveal the step-by-step Propolis autopsy.

Propolis Cognitive Error Autopsy

Official Correct Choice:
Option B: \( \text{CO} \)
Concept:

A coordinate covalent (dative) bond is formed when one atom provides both electrons for a shared pair to complete the octet of another atom.

Formula:

$$ :\text{C} \equiv \text{O}: $$

Solution:

  • In Carbon Monoxide (CO), Carbon has 4 valence electrons and Oxygen has 6.


  • They form two normal covalent bonds, giving Oxygen 8 electrons (stable), but Carbon only has 6.


  • To stabilize Carbon, Oxygen donates a lone pair to form a third bond (a coordinate covalent bond). Thus, CO possesses a triple bond: two normal and one dative.


Why other options are incorrect:

  • Option A, Option C, Option D: All atoms in these molecules complete their octets through standard mutual sharing of electrons. No lone pair donation is required.

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