Significant Figures for Calculations with Molar Masses

[Ria Nawathe 1C]

Are molar masses considered measured values or defined constants?

[Jessica Katz]

The molar masses are defined constants so they do not affect the significant figures that need to be included in your answer. I think it's because every periodic table could have the molar masses rounded to a different number and because they are the same in every single problem so they don't influence your final answer.

[Aydin Karatas 1F]

You can consider them as constants because they are known values. Sig figs will be determined from other non-constant, values given in a problem.

[Nika Gladkov 1A]

To add on to the previous replies, molar masses could also be adjusted to the level of accuracy that you need so that they don't interfere with calculations. If the source that you are using doesn't have the correct number of significant figures, and you think that it is a significant issue, you could try to find another source that gives more significant figures.

[Crystal Yu 1D]

Molar masses are defined constants.

For me, the easiest way to determine how many sig figs I should be using in my answer is by looking back at the problem and the given values. Generally the values given in the questions are the ones that you will begin your calculations with. The given values are then adjusted using defined constants, ratios of moles, etc as you solve the problem.

I'm not sure if my phrasing was the best, but I hope this makes sense!

[Kaiya_PT_1H]

To add on to the previous replies, molar masses could also be adjusted to the level of accuracy that you need so that they don't interfere with calculations. If the source that you are using doesn't have the correct number of significant figures, and you think that it is a significant issue, you could try to find another source that gives more significant figures.

Would it be better to adjust the molar mass to match the significant figures rest of the numbers in the problem, or would that make the result less accurate?