How many moles of [tex]$Mg$[/tex] are present in [tex]$2.5 \times 10^{25}$[/tex] atoms of [tex]Mg[/tex]?

A. [tex][tex]$1.51 \times 10^{49}$[/tex][/tex] moles
B. 41.5 moles
C. [tex]$4.15 \times 10^{47}$[/tex] moles
D. 0.415 moles



Answer :

To determine the number of moles from a given number of atoms, we use Avogadro's number, which is [tex]\( 6.022 \times 10^{23} \)[/tex] atoms per mole.

The formula to find the number of moles (n) is given by:

[tex]\[ n = \frac{\text{number of atoms}}{\text{Avogadro's number}} \][/tex]

Here, we are given:

- The number of atoms of Magnesium (Mg) = [tex]\( 2.5 \times 10^{25} \)[/tex]
- Avogadro's number = [tex]\( 6.022 \times 10^{23} \)[/tex]

Now, substitute these values into the formula:

[tex]\[ n = \frac{2.5 \times 10^{25}}{6.022 \times 10^{23}} \][/tex]

Upon performing this division, we find that:

[tex]\[ n \approx 41.514 \][/tex]

This indicates the number of moles of Magnesium (Mg) present in [tex]\( 2.5 \times 10^{25} \)[/tex] atoms Mg is approximately 41.5 moles.

Therefore, the correct answer is:

41.5 moles