Q2.4CYL

Question

A sample of magnesium is found to contain 78.70% of 24Mg atoms (mass 23.98 amu), 10.13% of 25Mg atoms (mass 24.99 amu), and 11.17% of 26Mg atoms (mass 25.98 amu). Calculate the average mass of a Mg atom.

Step-by-Step Solution

Verified
Answer

24.31 amu

1Step1: Given
  1. 78.70% of 24Mg atoms (mass 23.98 amu), 
  2. 10.13% of 25Mg atoms (mass 24.99 amu), and 
  3. 11.17% of 26Mg atoms (mass 25.98 amu)
2Step 2: Average mass

( 0.7870 x 23.98) + (0.1013 x 24.99) + (0.1117 x 25.98)

= 18.87 + 2.537 + 2.896

= 24.297 amu ~ 24.3 amu