# Chemical Forums

## Chemistry Forums for Students => High School Chemistry Forum => Topic started by: Tom on June 11, 2004, 11:59:32 AM

Title: molar mass
Post by: Tom on June 11, 2004, 11:59:32 AM
Can anyone tell me which one of these is the molar mass of Na2CO3? The 2 and the 3 are suppose to be subscripted, having trouble trying to accomplish this using the UBBC.

a.   106 g/mol
b.   50.0 g/mol
c.   41.0 g/mol
d.   76.5 g/mol
Title: Re:molar mass
Post by: jdurg on June 11, 2004, 03:36:39 PM
Tom, we don't mind helping you out with some chemistry homework/problems every now and then, but it seems as if you are asking us to answer all the homework questions you are receiving.  We can help get you on your way to solving the questions yourself, but if we answer everything for you you'll never learn the important concepts needed to master chemistry.  Questions such as the one you are asking in this thread are very simple questions that can you can answer for yourself by doing just a teency bit of research.   ;D
Title: Re:molar mass
Post by: Tom on June 11, 2004, 04:18:14 PM
I understand what you mean and I do appreciate all of your help. What I generally do is compare my results with what your results/opinions are as and the data listed in my text book and other sources.

As for this question I came up with 106 g/mol or to be specific 105.98 g/mol

How:
By using this formula and calculation;
(2)(22.989) + (12.0112) + 3(15.9994) = 105.98 g/mol

Na (amu) = 22.989
C   (amu) = 12.0112
O  (amu) = 15.9994
Title: Re:molar mass
Post by: jdurg on June 11, 2004, 04:27:49 PM
That would be correct.   ;D  If you include the answers you came up with in your original questions, then I think we'd be able to help you out a lot more and we wouldn't feel as if we were just "giving" you the answers.  By showing us the answer you came up with and how you came up with it, we can also help you along the proper path.  (Or in this case, tell you that you are 100% right and you used the proper method of coming up with the answer).   ;D
Title: Re:molar mass
Post by: Mitch on June 11, 2004, 08:53:15 PM
It's written in the "READ THIS BEFORE POSTING" thread in this forum. Guideline 3.