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Chemistry Forums for Students => Undergraduate General Chemistry Forum => Topic started by: The Tao on February 14, 2007, 02:20:15 AM

Title: Empirical Formula
Post by: The Tao on February 14, 2007, 02:20:15 AM

I was given a few homework questions in which I needed to find the empirical formula for different percentages of Nitrogen and Oxygen. However, I found out that there are a few, "N2O, NO, NO3." I'm a little confused, because I thought that the empirical formula represented the smallest ratio that the two elements could combine. Is this true, or does it mean, for example that NO3 is the smallest possible ratio that Nitrate specifically can combine, rather than a general compound containing N, and O.

Edit: Simple typo

Title: Re: Empirical Formula
Post by: Bakegaku on February 14, 2007, 04:41:21 AM

The empirical formula shows the simplest ratio of elements in a compound.  So, NO₃ would be both the molecular formula and the empirical formula because there's no common denominator.

For small molecules, this is almost always the case.  But in glucose, for example, the molecular formula is C_{6H12O6, but 6:12:6 can be simplified to 1:2:1, so the empirical formula would be CH2O}