Unformatted text preview: EXERCISE: Calculation of the Molecular formula of a Compound. Explanation: The molecular formula of a compound is the actual formula of the compound. In
many instances, however, the empirical and molecular formulas are equal. The process of solving problems is similar to the empirical formula problems except we have to take into
account the molecular weight Example: Comparisons of empirical and molecular formulas Empirical formula Molecular Formula
—— NaCl Note: Molecular formulas can usually be simpliﬁed by dividing by a common factor. Example: A compound was found to have a molecular weight of 78 g/mol and have a percent composition of 92.3% C and 7.7% H. Calculate the empirical and
molecular formulas. Solution: Fill in the table below. Divide by ' Answer,‘ — .
Answer smallest ’ subscripts in
answer formula 12 7692 7692 — Divide the percent by the molar mass of the element. Leave the answer to 2-3 decimals for
greater accuracy. Percent of Molar'mass
element of element C 92.3 / 12 7.692 H 7.7/1 7.7 Empirical formula CH = 13 g/mol CHE 164: General Chemistry 1 ...
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- Fall '11