Naturally occurring chlorine is composed of two isotopes: 75.76% Cl-35 (mass 34.9688 amu) and 24.24% Cl-37 (mass 36.9659 amu). Naturally occurring oxygen is composed of three isotopes: 99.757% O-16 (mass 15.9949 amu), 0.038% O-17 (mass 16.9991 amu), and 0.205% O-18 (mass 17.9991 amu). The compound dichlorine monoxide is composed of two chlorine atoms and one oxygen atom bonded together to form the Cl₂O molecule. How many Cl₂O molecules of different masses naturally exist? Give the masses of the three most abundant Cl₂O molecules.

Key Concepts

Isotopes

Isotopes are variants of a chemical element that have the same number of protons but different numbers of neutrons, resulting in different atomic masses. For example, chlorine has two stable isotopes, Cl-35 and Cl-37, which contribute to the average atomic mass of chlorine in nature. Understanding isotopes is crucial for calculating the mass of compounds formed from elements with multiple isotopes.

Molecular Mass Calculation

Molecular mass is the sum of the atomic masses of all atoms in a molecule. In the case of dichlorine monoxide (Cl2O), the molecular mass is calculated by adding the masses of two chlorine atoms and one oxygen atom. This concept is essential for determining the different possible masses of Cl2O molecules based on the isotopes of chlorine and oxygen present.

Natural Abundance

Natural abundance refers to the relative proportions of different isotopes of an element found in nature. For instance, the natural abundance of Cl-35 and Cl-37 affects the average mass of chlorine used in molecular mass calculations. This concept is important for predicting the most common isotopic combinations in compounds like Cl2O and determining the masses of the most abundant molecules.