Question

rhenium (re) consists of two stable isotopes, 185 re and 187 re. the average atomic mass of re is 186.2amu. what is the mole percent of 185 re in rhenium? (a) 40% (b) 50% (c) 60% (d) 62%

Answer 1

To calculate the mole percent of 185 Re in rhenium, you can use the formula (mass of 185 Re / total mass of rhenium) ×100% assuming the atomic masses of 185 Re and 187 Re are close to 185 amu and 187 amu, respectively.

Step-by-step explanation:

The mole percent of 185 Re in rhenium can be calculated using the formula:

Mole percent = (mass of 185 Re / total mass of rhenium) × 100%

Given that the average atomic mass of rhenium is 186.2 amu, we can assume that the atomic masses of 185 Re and 187 Re are close to 185 amu and 187 amu, respectively.

Assuming x is the mole percent of 185 Re: x × 185 + (100 - x) × 187 = 186.2

Solving this equation will give us the value of x, which represents the mole percent of 185 Re in rhenium.