Empirical and Molecular Formulas

Front

What is an empirical formula?

Back

An empirical formula represents the simplest whole-number ratio of atoms of each element in a compound.

Front

What is a molecular formula?

Back

A molecular formula shows the actual number of atoms of each element in a molecule of a compound.

Front

How do you calculate the molar mass of a compound?

Back

Add the atomic masses of all the atoms in the molecular formula.

Front

What does a subscript in a chemical formula indicate?

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A subscript indicates the number of atoms of the element in the molecule.

Front

What is the empirical formula of a compound with a molecular formula of C6H12O6?

Back

The empirical formula is CH2O.

Front

How many hydrogen atoms are in the molecular formula C3H8?

Back

There are 8 hydrogen atoms.

Front

If a compound has a molar mass of 58 g/mol and an empirical formula of CH2, what is its molecular formula?

Back

The molecular formula is C4H8.

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What is the significance of the empirical formula in chemistry?

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It provides a simplified representation of the composition of a compound.

Front

How do you determine the empirical formula from percent composition?

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Convert the percentages to grams, then to moles, and simplify the ratio.

Front

What is the empirical formula for a compound containing 75% carbon and 25% hydrogen?

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The empirical formula is CH4.