Question

The average atomic mass of magnesium is 24.31 amu this magnesium is composed of 79% mole of 24 cm and remaining 21

Answer 1

Explanation:

Let the moles of magnesium to be x .

So, the moles of 21% will be (21-x).

Now, to calculate the average atomic mass of magnesium we have to let the total mass to be as 100 and hence the average of all these will be equal to 24.31AMU .

To calculate average atomic mass for finding x:-

{79*24 + 26*x + (21-x)25}/100 = 24.31

1896 + 26x + 525 -25x = 2431

x = 10 .

Hence, the mole of magnesium is 10.