Suppose a student needs to standardize a sodium thiosulfate, Na2S2O3,Na2S2O3, solution for a titration experiment. To do so, he

Answer: The percentage abundance for isotope is 3.09 %.

Explanation:

The average atomic mass of an element is calculated by taking the sum of the masses of all isotopes weighted by their respective natural fractional abundances.

To compute average atomic mass, the following formula is applied:

  .....(1)

From the information provided:

Let the fractional abundance for isotope be 'x'

• For isotope:

Mass of isotope = 27.9769 amu

Percentage abundance of isotope = 92.22 %

Fractional abundance for isotope = 0.9222

• For isotope:

Mass of isotope = 28.9764 amu

Percentage abundance for isotope = 4.68%

Fractional abundance of isotope = 0.0468

• For isotope:

Mass of isotope = 29.9737 amu

Fractional abundance for isotope = x

• The average atomic mass of silicon is 28.084 amu

By inserting these values into equation 1, we derive:

To convert this fractional abundance into a percentage, multiply by 100:

This shows that the percentage abundance for isotope is 3.09 %.