Question

The element rhenium (re) has two naturally occurring isotopes, 185re and 187re, with an average atomic mass of 186.207 amu. rhenium is 62.60% 187re, and the atomic mass of 187re is 186.956 amu. calculate the mass of 185re.

Answer 1

To calculate the mass of 185Re, we need to use the average atomic mass and the percentage abundance of 187Re. Using the given information, the mass of 185Re is approximately 183.26 amu.

Step-by-step explanation:

To calculate the mass of 185Re, we need to use the average atomic mass and the percentage abundance of 187Re. Let's assume the mass of 185Re is x amu.

Now, we can set up an equation using the given information:

(62.60/100) (187.956 amu) + (37.40/100) (x amu) = 186.207 amu

→ (0.626) (187.956) + (0.374) (x) = 186.207

Simplifying the equation:

117.614376 + 0.374x = 186.207

Now, we can solve for x:

0.374x = 186.207 - 117.614376

→ 0.374x = 68.592624

→ x = 68.592624/0.374

→ x ≈ 183.26 amu

Therefore, the mass of 185Re is approximately 183.26 amu.