Question

Chlorine has two isotopes, 35Cl and 37Cl that have the respective percent abundance's of 75.77% and 24.23% and masses of 34.9688 amu and 36.9659 amu. Calculate the atomic weight of chlorine.

Answer 1

The answer to your question is 35.4527 g

Step-by-step explanation:

Data

Cl-35 abundance = 75.77 % mass Cl-35 = 34.9688

Cl-37 abundance = 24.23 % mass Cl-37 = 36.9659

Process

1.- Convert the percents to decimals

75.77% = 75.77/100 = 0.7577

24.23% = 24.23/100 = 0.2423

2.- Find the atomic weight

Average atomic weight = Abundance 1 x Mass Cl-35 +

Abundance 2 x Mass Cl-37

Substitution

Average atomic weight = (0.7577)(34.9688) + (0.2423 x 36.9659)

Simplification

Average atomic weight = 26.4959 + 8.9568

Result

Average atomic weight = 35.4527 g