Question

the graph below shows the potential energy as a function of internuclear distance for molecular oxygen, o=o, and an unknown heteronuclear diatomic molecule, a - b. based on the data in the graph, which of the following correctly identifies the diatomic molecule a - b? choose 1 answer: a carbon monoxide, c≡o b bromine monofluoride, br - f c sulfur monoxide, s=o d iodine monochloride, i - cl

Explanation:

Step1: Analyze bond - energy and bond - length relationship

The depth of the potential - energy well is related to bond energy, and the position of the minimum of the potential - energy curve is related to bond length. A stronger bond has a deeper potential - energy well and a shorter bond length. The $A - B$ molecule has a shorter bond length and a higher bond energy compared to $O = O$.

Step2: Consider bond orders and atomic sizes

Carbon monoxide ($C\equiv O$) has a triple bond. Triple bonds are shorter and stronger than double bonds (like in $O = O$). The other options (Bromine monofluoride $Br - F$, Sulfur monoxide $S = O$, Iodine monochloride $I - Cl$) have single or double bonds and larger atomic - size combinations which result in longer bond lengths and lower bond energies compared to a triple - bonded molecule.

Answer:

A. Carbon monoxide, $C\equiv O$