Download Molar mass review, empirical vs molecular.notebook and more Exams Chemistry in PDF only on Docsity! Molar mass review, empirical vs molecular.notebook December 09, 2015 Dec 7-7:31 AM Warm up 1) Define molar mass 2) How many mols are in 24.0 grams of C 3) How much does half a mol of water weigh? Nov 16-7:26 AM More Practice: 1) What is the molar mass of C2H7 given to 3 sig figs? 2) How many mols of C2H7 are in 321g? 3) What is the percent weight of C in C2H7? 4)How many grams would 0.750 mols of C2H7 weigh? Molar mass review, empirical vs molecular.notebook December 09, 2015 Nov 16-7:31 AM Molecular vs Empirical Formulas Empirical formulas are the ratio of atoms in a molecule Molecular formulas are the COMPLETE number of atoms in an element. Nov 16-7:32 AM Examples Empirical formula of CH This means that for every atom of carbon, there is one atom of hydrogen. Molecular formulas with the same ratio - acetylene - C2H2 benzene - C6H6 Molar mass review, empirical vs molecular.notebook December 09, 2015 Nov 16-8:46 AM 1. Calculate the empirical formula. Assume 100 g of the compound, which will contain 38.70 g carbon, 9.75 g hydrogen and the rest oxygen ? g O = 100 g - 38.70 g C - 9.75 g H = 51.55 g O. 2. Calculate the moles of each element present: 3. Next calculate the ratio of molecular weight to empircal formula weight. The molecular weight is given. The empirical formula is CH3O, so the empirical formula weight is 12.01 + 3 (1.008) + 16.00 = 31.03. Therefore the molecular formula is twice the empirical formula: C2H6O2. Dec 7-7:33 AM A sample with a molar mass of 34.00 g/mol is found to consist of 0.44g H and 6.92g O. Find its molecular formula. Molar mass review, empirical vs molecular.notebook December 09, 2015 Dec 7-7:36 AM If 4.04g of N combine with 11.46g O to produce a compound with a molar mass of 108.0 g/mol, what is the molecular formula of this compound? Dec 7-7:36 AM The empirical formula for trichloroisocyanuric acid, the active ingredient in many household bleaches, is OCNCl. The molar mass of this compound is 232.41g/mol. What is the molecular formula of trichloroisocyanuric acid. Molar mass review, empirical vs molecular.notebook December 09, 2015 Dec 7-7:37 AM The molar mass of a compound is 92g/mol. Analysis of a sample of the compound indicates that it contains 0.606g N and 1.390g O. Find its molecular formula. Dec 7-7:37 AM Determine the molecular formula of a compound with an empirical formula of NH2 and a formula mass of 32.06 g/mol.
