Determining Empirical and Molecular Formulas of Compounds, Study notes of Chemistry

Download Determining Empirical and Molecular Formulas of Compounds and more Study notes Chemistry in PDF only on Docsity! Empirical and Molecular Formulas Other kinds of chemical formulas are empirical and molecular formulas. Empirical Formulas Empirical formulas give the lowest whole number ratio of the atoms in a compound. C2HCl Steps to determine Empirical Formula • 1. Assume 100 gram sample • 2. Convert % (if given to grams) • 3. Change each mass to moles • 4. Divide ALL moles by the smallest # of moles • *5. Do not round: if 1.5 moles then double everything to obtain a whole # (3) Empirical formulas can be calculated using experimental data:  Given that a certain compound is 69.58% Ba, 6.090% C and 24.32% O, calculate the empirical formula of this compound. Assume that you have 100.00 g of the compound: 69.58% Ba = 69.58 g Ba 6.090% C = 6.090 g C 24.32% O = 24.32 g O Empirical Formula  Divide through each value by the smallest number of moles to get a 1 : 1.001 : 2.999 ratio, which rounds of nicely to give the formula BaCO3 Try the quiz 1. Honors Chem: http://www.quia.com/quiz/618428.h tml 2. Academic Chem: http://www.quia.com/quiz/363518.h tml Use the empirical formula to determine the molecular formula •Empirical Formula is •Molecular Formula –Has a mass of 60 g/m CH4N