Percent Composition • The percent by mass of each element in the compound
Percent Composition Example 1 • Determine the percent composition of calcium carbonate, Ca. CO 3.
Percent Composition Example 2 • Determine the percent composition of magnesium nitrate, Mg(NO 3)2.
Empirical Formula • A chemical formula showing the simplest ratio of elements in a compound
Molecular Formula • A formula that shows the actual number of each element in a compound.
Empirical & Molecular Formula Ethyne, C 2 H 2 Styrene, C 8 H 8 • Empirical Formula • Molecular Formula
Empirical Formula Example 3 A compound is found to contain 25. 9% nitrogen and 74. 1% oxygen. Determine the empirical formula.
Empirical Formula Example 4 • What is the empirical formula for a compound which contains 67. 1% zinc and the rest oxygen?
Empirical Formula Example 5 • Find the empirical formula of a compound that contains 2. 374% H, 14. 14% C, and 83. 48% Cl.
Empirical Formula Example 6 • A compound contains 57. 54% C, 3. 45% H, and 39. 01% F. What is its empirical formula?
Molecular Formula Example 7 • Calculate the molecular formula of a compound whose molar mass is 60. 0 g/mol and the empirical formula is CH 4 N.
Molecular Formula Example 8 • A compound is found to contain 50. 05 % sulfur and 49. 95 % oxygen by weight. • What is the empirical formula for this compound? • The molecular weight for this compound is 64. 07 g/mol. What is its molecular formula?