Question

What is the average atomic mass of Chlorine if 75.77% exists as ³⁵Cl (34.968852 amu) and 24.23% exists as ³⁷Cl (36.965903 amu)?

Answer 1

The average atomic mass of chlorine is calculated using the given isotope masses and percent abundances, resulting in an average atomic mass of 35.45 amu.

Step-by-step explanation:

The average atomic mass of chlorine can be calculated using the percent abundances and the masses of its naturally occurring isotopes. Using the given abundances, chlorine-35 (Cl-35) with a mass of 34.969 amu and an abundance of 75.77%, and chlorine-37 (Cl-37) with a mass of 36.966 amu and an abundance of 24.23%, we perform the calculation as follows:

For Cl-35: (0.7577 × 34.969 amu) = 26.50 amu

For Cl-37: (0.2423 × 36.966 amu) = 8.95 amu

Adding the two contributions together gives us: (26.50 amu + 8.95 amu) = 35.45 amu.

Thus, the average atomic mass of chlorine is 35.45 amu, taking into account the isotopic composition and applying significant figure rules.