Answer:

Explanation:
The molar mass, or mass of 1 mole of a substance, is used to convert grams to moles. We are given the molar mass of chlorine. It is 35.45 grams per mole.
We convert using dimensional analysis, so we must set up a conversion factor using the molar mass.

We are converting 10.0 grams of chlorine to moles, so we must multiply the conversion factor by this value.

Flip the conversion factor. The result is equivalent and allows us to cancel the units of grams of chlorine.




The original value of grams (10.0) has 3 significant figures, so our answer must have the same. For the number we found, that is the thousandth place. The 0 in the ten-thousandth place tells us to leave the 2 in the thousandth place.

Approximately <u>0.282 moles of chlorine</u> are in 10.0 grams of chlorine.