Empirical Formulas

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What is an empirical formula?

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An empirical formula is the simplest whole-number ratio of the elements in a compound.

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How do you calculate the empirical formula from percentage composition?

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1. Convert percentages to grams. 2. Convert grams to moles. 3. Divide by the smallest number of moles to find the ratio.

Front

What is the empirical formula for a compound with 72.2% magnesium and 27.8% nitrogen?

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Mg3N2

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Which pair has the same empirical formula: NaCrO4 and Na2Cr2O7, or C2H4O2 and C6H12O6?

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C2H4O2 and C6H12O6

Front

How do you determine the empirical formula from a given mass percentage of elements?

Back

Convert the mass percentages to moles, find the simplest mole ratio, and write the empirical formula.

Front

What is the empirical formula for Na, P, and O with percentages 42.07%, 18.89%, and 39.04% respectively?

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Na3PO4

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What is the empirical formula for N2S3?

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N2S3 (it is already in simplest form).

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How do you find the empirical formula for a compound with 40.05% sulfur and 59.95% oxygen?

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SO3

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What is the significance of an empirical formula in chemistry?

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It provides the simplest ratio of elements in a compound, which is useful for understanding its composition.

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What is the difference between empirical and molecular formulas?

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An empirical formula shows the simplest ratio of elements, while a molecular formula shows the actual number of atoms in a molecule.