Final answer:
There can be three naturally existing Cl₂O molecules of different masses due to the isotopic variations of chlorine. These molecules vary in mass based on the combination of Cl-35 and Cl-37 isotopes within Cl₂O. These variations result in Cl₂O molecules that are isotopologues, molecules that differ only in their isotopic composition.
Step-by-step explanation:
The student asks about the naturally existing Cl₂O molecules of different masses. Cl-35 and Cl-37 are the two isotopes of chlorine that are found in nature. These isotopes have differing atomic masses, but for molecular substances like Cl₂O, only whole molecules can exist. Hence, for Cl₂O, the mass distinctions arise from these isotopic differences in elemental chlorine within the molecule. Cl-35 has an atomic mass of 34.97 atomic mass units (amu), and Cl-37 has an atomic mass of 36.97 amu. Since chlorine is a diatomic molecule in Cl₂O, the isotopic variations would be Cl₂(35-35), Cl₂(35-37), and Cl₂(37-37), resulting in different masses for Cl₂O.
Considering the isotopic composition of chlorine, where 75.77% are Cl-35 and 24.23% are Cl-37, there are three types of Cl₂O molecules that could exist naturally, reflecting the combinations of chlorine isotopes within the molecule. These would have different molecular masses due to the varying atomic masses of the chlorine isotopes. To find the differing molecular masses of Cl₂O, we would add the mass of oxygen (16 amu for an O-16 isotope) to the combined mass of the two chlorine atoms for each isotope combination.