Empirical Formulas

Front

What is an empirical formula?

Back

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

Front

How do you calculate the empirical formula from percent composition?

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1. Convert the percentage of each element to grams (assuming 100g total). 2. Convert grams to moles by dividing by the atomic mass. 3. Divide all mole values by the smallest number of moles to find the simplest ratio.

Front

What is the empirical formula for a compound with 52.14%C, 13.13%H, and 34.73%O?

Back

CH₃CH₂OH

Front

What is the empirical formula for a compound with 63.53%Fe and 36.47%S?

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FeS

Front

What is the empirical formula for a compound with 23.3%Co, 25.3%Mo, and 51.4%Cl?

Back

Co₃Mo₂Cl₁₁

Front

What is the empirical formula for a compound with 16.3%C, 32.1%Cl, and 51.6%F?

Back

C₃Cl₂F₆

Front

How do you find the percentage of an element in a compound?

Back

To find the percentage of an element in a compound, divide the mass of the element in one mole of the compound by the molar mass of the compound, then multiply by 100.

Front

What is the % nitrogen in NH₄NO₃?

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35.0 %

Front

What is the significance of the empirical formula in chemistry?

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The empirical formula provides essential information about the composition of a compound, which is crucial for understanding its properties and reactions.

Front

What is the difference between empirical and molecular formulas?

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