Molecular Formulas and Empirical Formulas

Butyric acid, a component of rancid butter, has a vile stench. Burning 0.440 g of butyric acid in excess oxygen yields 0.882 g of CO2 and 0.360 g of H2 O as the only products. The molar mass of butyric acid is 88 g/mol. What are its empirical formula and molecular formula ... 

C03-0089. Combustion analysis of 0.60 g of an unknown organic compound that contained only C, H, and O gave 1.466 g of carbon dioxide and 0.60 g of water in a combustion analysis. Mass spectral analysis showed that the compound had a molar mass around 220 g/mol. Determine the empirical formula and molecular formula. 

Calculations involving hydrates involve using the same techniques you have already practised for determining percent by mass, empirical formulas, and molecular formulas. 

Concept Mapping Design a concept map that illustrates the mole concept. Include moles, Avogadro s number, molar mass, number of particles, percent composition, empirical formula, and molecular formula. 

Before beginning, we need to understand the distinction between two types of chemical formulas, empirical formulas and molecular formulas. When the subscripts in a chemical formula represent the simplest ratio of the kinds of atoms in the compound, the formula is called an empirical formula. Most ionic compounds are described with empirical formulas. For example, chromium(III) oxide s formula, Cr203, is an empirical formula. The compound contains two chromium atoms for every three oxide atoms, and there is no lower ratio representing these relative amounts. 

Explain the difference between molecular formulas and empirical formulas. Give an example of a substance whose empirical formula is different from its molecular formula. Give an example of a substance whose empirical formula and molecular formula are the same. 

There are two broad classes of formulas for compounds empirical formulas and molecular formulas. The empirical formula shows the simplest ratio of elements in a compound and uses the smallest possible set of subscript numbers. Empirical formulas are also called simple formulas. The formulas of a// ionic compounds are empirical formulas. Since ionic compounds do not exist as molecules, their formulas are not molecular formulas. The formulas calculated from percent composition data are empirical formulas. (We ll get to these calculations later.)... 

Define molecular formula and empirical formula. What are the similarities and differences between the empirical formula and molecular formula of a compound ... 

The empirical formula and molecular formula are calculated as in Chapter 4. 

Distinguish between empirical formulas and molecular formulas. (Section 2.6)... 

Strategy To determine the molecular formula, we first need to determine the empirical formula. Comparing the empirical molar mass to the experimentally determined molar mass will reveal the relationship between the empirical formula and molecular formula. 

The molecular formula represents the actual number of atoms in a molecule of a simple covalent substance. The empirical formula and molecular formula may be identical for a molecule or they may be different. The empirical formula may be found by dividing the coefficients in the molecular formula by the highest common factor. 

Ascorbic acid (vitamin C) contains C, H, and O. In one combustion analysis, 5.24 g of ascorbic acid yields 7.86 g CO2 and 2.14 g H2O. Calculate the empirical formula and molecular formula of ascorbic acid given that its molar mass is about 176 g. 

The percent composition of a certain compound is 54.5% carbon, 9.1% hydrogen, and 36.4% oxygen. The formula weight of this compound is 88.0 g/mol. Calculate both the empirical formula and molecular formula of this compound. 

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