Select the correct answer.

How many moles are contained in [tex]$3.131 \times 10^{24}$[/tex] particles?

A. [tex]5.199 \, \text{mol}[/tex]

B. [tex]18.85 \, \text{mol}[/tex]

C. [tex]0.5199 \times 10^{23} \, \text{mol}[/tex]

D. [tex]1.885 \times 10^{47} \, \text{mol}[/tex]



Answer :

To determine how many moles are contained in [tex]\(3.131 \times 10^{24}\)[/tex] particles, we use Avogadro's number, which is [tex]\(6.022 \times 10^{23}\)[/tex] particles per mole. Here is the step-by-step process to find the number of moles:

1. Understand the relationship: Avogadro's number tells us how many particles (atoms, molecules, etc.) are in one mole of a substance. This number is given as [tex]\(6.022 \times 10^{23}\)[/tex] particles per mole.

2. Set up the formula: The number of moles ([tex]\(n\)[/tex]) can be found using the formula:
[tex]\[ n = \frac{\text{Number of particles}}{\text{Avogadro's number}} \][/tex]

3. Insert the given values:
[tex]\[ n = \frac{3.131 \times 10^{24} \text{ particles}}{6.022 \times 10^{23} \text{ particles/mole}} \][/tex]

4. Perform the division: To find the exact number of moles, divide [tex]\(3.131 \times 10^{24}\)[/tex] by [tex]\(6.022 \times 10^{23}\)[/tex]:
[tex]\[ n = \frac{3.131}{6.022} \times 10^{24 - 23} \][/tex]

5. Simplify the calculation: This simplifies to:
[tex]\[ n = \frac{3.131}{6.022} \times 10^1 \][/tex]
[tex]\[ n \approx \frac{3.131}{6.022} \times 10 \][/tex]

6. Calculate the approximate value: Carry out the division:
[tex]\[ n \approx 0.5199 \times 10 \][/tex]
[tex]\[ n \approx 5.199 \][/tex]

So, the calculated number of moles is approximately [tex]\(5.199\)[/tex].

7. Compare with the given options:
- A. [tex]\(5.199 \text{ mol}\)[/tex]
- B. [tex]\(18.85 \text{ mol}\)[/tex]
- C. [tex]\(0.5199 \times 10^{23} \text{ mol}\)[/tex]
- D. [tex]\(1.885 \times 10^{47} \text{ mol}\)[/tex]

The calculation shows that the number of moles is closest to the option A [tex]\(5.199 \text{ mol}\)[/tex].

Therefore, the correct answer is A.