Answer :
Answer:
[tex]\boxed {\boxed {\sf About \ 2.96 \ moles \ of \ Argon}}[/tex]
Explanation:
To convert from grams to moles we must use the molar mass, which is found on the Periodic Table.
- Argon: 39.9 g/mol
Use the molar mass as a ratio.
[tex]\frac{39.9 \ g \ Ar}{1 \ mol \ Ar}[/tex]
Multiply by the given number of grams: 118
[tex]118 \ g \ Ar *\frac{39.9 \ g \ Ar}{1 \ mol \ Ar}[/tex]
Flip the fraction so the grams of argon will cancel each other out.
[tex]118 \ g\ Ar * \frac{1 \ mol \ Ar}{39.9 \ g \ Ar}[/tex]
[tex]118 * \frac{ 1 \ mol \ Ar}{39.9 \ g \ Ar}[/tex]
[tex]\frac {118 \ mol \ Ar }{ 39.9 }[/tex]
[tex]2.95739348 \ mol \ Ar[/tex]
The original measurement of grams had 3 significant figures, so our answer must have 3 sig figs.
For the number we calculated, that is the hundredth place. The 7 in the thousandth place tells us to round the 5 to a 6.
[tex]2.96 \ mol \ Ar[/tex]
There are about 2.96 moles of Argon in 118 grams.