Respuesta :
[tex]1.985 \times 10^{24} \text { atoms }[/tex] is the calculated number of atoms in 75.8 g of Na
Explanation:
In order to go from mass of sodium to atoms of sodium, we have to do two things:
- Convert mass of Na to moles of Na using the molar mass of Na as a conversion factor
- Convert moles of Na to atoms of Na using Avogadro's number ([tex]6.02 \times 10^{23}[/tex]) as a conversion factor
Step 1:
To calculate the number of atoms in a Na sample, divide its weight in grams by the amu atomic mass from the periodic table
We know the Molar mass of Na = 22.989770 g / mole
Given weight of Na in grams = 75.8 g
[tex]75.8 g \times \frac{1 \mathrm{mole}}{22.989770 \mathrm{g}}=3.297 \mathrm{mole}[/tex]
Step 2:
Multiply the obtained result by Avogadro's number ([tex]6.02 \times 10^{23}[/tex])
[tex]3.297 \text { mole } \times \frac{6.02 \times 10^{23} \text { atoms }}{1 \text { mole }}=19.85 \times 10^{23} \text { atoms }=1.985 \times 10^{23} \text { atoms }[/tex]
