Posted: Tue Oct 02, 2018 5:28 pm
On the video module under Empirical and Molecular formulas, the example of finding the molecular formula for vitamin C, the molar mass given for the compound is 176.14gmol^-1. Then I take the empirical formula C3H4O3 and multiply it by 2.000 to get the molecular formula C6H8O6. What I am confused on is that in the video Professor Lavelle says that we can check the molar mass by taking the molecular formula and adding up what it would weigh if we had one mole of this compound. So, doing (6 C x 12.01g) + (8 H x 1.008) + (6 O x 16) should equal the given molar mass (176.14gmol^-1). But, when I do it, I get 176.124. Does this have to do with significant figures or is he rounding to get 176.14?