Chlorine has two isotopes, 35Cl and 37Cl, whose respective abundances are 75.77% and 24.23% and masses are 34.9688 amu and 36.9659 amu. Calculate the atomic mass of chlorine.
A) 37.54 amu
B) 36.65 amu
C) 35.45 amu
D) 34.97 amu
E) 36.97 amu

Question

Quizplus · Accepted Answer

The atomic mass of chlorine can be calculated using the formula:

atomic mass = (abundance of isotope 1 x mass of isotope 1) + (abundance of isotope 2 x mass of isotope 2)

Plugging in the values given:
atomic mass = (0.7577 x 34.9688) + (0.2423 x 36.9659)
atomic mass = 26.4935 + 8.9595
atomic mass = 35.453 amu

Therefore, the atomic mass of chlorine is 35.453 amu, which corresponds to option C.

Chlorine Has Two Isotopes, 35Cl and 37Cl, Whose Respective Abundances