Which of the following does NOT represent the formation of a coordinate covalent bond? (A) H H H : C : Cl H H (B) H H : O : H + H^+ (C) H H H : N : H + H^+ (D) :O: :O: The diagram shows the pH values of some substances. - HSC - SSCE Chemistry - Question 13 - 2060 - Paper 1

To identify which option does NOT depict a coordinate covalent bond, we must first understand the concept of coordinate covalent bonding. A coordinate covalent bond is formed when one atom donates both of the electrons for the bond, typically represented by two dots around one of the atoms. We will analyze each option:

• (A) shows a typical covalent bond between carbon and chlorine, where electrons are shared but not coordinated.
• (B) demonstrates the oxygen atom accepting a hydrogen ion (H+), which indicates the formation of a coordinate bond, as the oxygen atom donates the pair of electrons it shares with hydrogen.
• (C) similarly shows nitrogen accepting a hydrogen ion, forming a coordinate covalent bond.
• (D) purely depicts two oxygen atoms forming a typical covalent bond (not coordinate).

Among all options, (B) represents the option that does NOT exemplify a traditional coordinate covalent bond formation as it highlights the donation of a hydrogen ion rather than an electron pair from one atom.