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### Rounding molar mass on the periodic table

Posted: Sun Oct 07, 2018 3:36 pm
Should you ever round molar mass from the periodic table based on sig figs or should you always use the given number without rounding?

### Re: Rounding molar mass on the periodic table

Posted: Sun Oct 07, 2018 3:39 pm
For calculations, use the given molar mass on the periodic table without rounding. Round based on the amount of sig figs at the end of your calculation.

### Re: Rounding molar mass on the periodic table

Posted: Sun Oct 07, 2018 3:40 pm
You can use the full number if you want as long as your final answer is with the correct number of sig figs. Or you can round to the number of sig figs in the problem and then solve, but I think the first way will get you a more accurate answer.

### Re: Rounding molar mass on the periodic table

Posted: Sun Oct 07, 2018 4:28 pm
I believe that the TAs are grading the exams are based on the least amount of sig figs stated in the problem. So it is safe to assume that you should use the given values of molar mass on the periodic table and then do the correct number of sig figs as your final answer.