Answer:
[tex]\boxed {\boxed {\sf 5.00 \ mol \ Ar }}[/tex]
Explanation:
To convert from mole to atoms, we must use Avogadro's Number: 6.022*10²³. This number tells us the particles (atoms, ions, molecules, etc.) in 1 mole of a substance. In this case, the particles are atoms of argon.
Let's create a ratio.
[tex]\frac {6.022*10^{23} \ atoms \ Ar}{1 \ mol \ Ar}[/tex]
Multiply by the given number of atoms.
[tex]3.01*10^{24} \ atoms \ Ar *\frac {6.022*10^{23} \ atoms \ Ar}{1 \ mol \ Ar}[/tex]
Flip the fraction so the atoms of argon will cancel.
[tex]3.01*10^{24} \ atoms \ Ar *\frac {1 \ mol \ Ar}{6.022*10^{23} \ atoms \ Ar}[/tex]
[tex]3.01*10^{24} *\frac {1 \ mol \ Ar}{6.022*10^{23}}[/tex]
[tex]\frac {3.01*10^{24} \ mol \ Ar}{6.022*10^{23}}[/tex]
[tex]4.998339422 \ mol \ Ar[/tex]
The original measurement of atoms has 3 significant figures, so our answer must have the same. For the number we calculated, that is the hundredth place. The 8 in the thousandth place tells us to round the 9 to a 0, which also rounds the 9 in the tenths place to a 0, then the 4 to a 5.
[tex]5.00 \ mol \ Ar[/tex]
There are 5.00 moles of argon.
