Question

Use the following information to determine the atomic mass of chlorine. Two isotopes are known: chlorine-35 (mass 35.0 amu) and chlorine-37 (mass = 37.0 amu). The relative abundances are 75.4% and 24.6%, respectively.

Answer 1

The average atomic mass of chlorine is calculated using the masses and relative abundances of its isotopes, resulting in an atomic mass of approximately 35.46 amu.

Step-by-step explanation:

To calculate the atomic mass of chlorine, considering its isotopes chlorine-35 and chlorine-37, we need to take their masses and relative abundances into account. The calculation is as follows:

For chlorine-35: atomic mass = 34.969 amu and percent abundance = 75.77%

For chlorine-37: atomic mass = 36.966 amu and percent abundance = 24.23%

We multiply each isotope's mass by its relative abundance (in decimal form) and sum the results to get the average atomic mass of chlorine:

(0.7577 × 34.969 amu) + (0.2423 × 36.966 amu) = 26.50 + 8.96 = 35.46 amu

Therefore, the average atomic mass of chlorine is approximately 35.46 amu, applying the rules of significant figures.

Answer 2

The atomic mass of chlorine is approximately 35.45 amu.

Step-by-step explanation:

The atomic mass of chlorine can be calculated by multiplying the mass of each isotope by its respective percent abundance, and then adding the products together. In this case, chlorine-35 has a mass of 34.969 amu and a percent abundance of 75.4%, while chlorine-37 has a mass of 37.0 amu and a percent abundance of 24.6%. Using these values, we can calculate the atomic mass of chlorine:

(0.754 x 34.969) + (0.246 x 37.0) = 35.45 amu

Therefore, the atomic mass of chlorine is approximately 35.45 amu.