Conversion Factors

[Elisa Bass 4L]

If a conversion factor is necessary in solving a problem, do the significant figures in that conversion factor matter?

[Mindy Kim 4C]

No, in problems only the significant figures given in the problem matter for the significant figures in your final answer. For example, if you use the conversion factor 35.45 g/mol, this number would not change the number of significant figures in your final answer. And if the problem gave 3.45 g as a given amount, this would affect the number of sig figs in your answer.

[Elisa Bass 4L]

What about when you are calculating molar mass and the problem gives you a rounded mass for an element, such as 16 g for oxygen or 1 g for hydrogen? Are those also considered conversion factors or do you use them when determining sig figs?

[Mindy Kim 4C]

I believe the same applies for molar masses given in the problem. Since these molar masses are still conversion factors, they would also not apply to significant figures in your final answer.