Empirical and Molecular Formula Practice Test

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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 determine the empirical formula from percent composition?

Back

Convert the percentage of each element to grams, then to moles, and simplify the mole ratio to the smallest whole numbers.

Front

Which of the following is an example of an empirical formula: C6H12O6, CH3COOH, or H2O?

Back

H2O is an empirical formula.

Front

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

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The empirical formula is Mg3N2.

Front

How do you find the molecular formula from the empirical formula?

Back

Multiply the empirical formula by a whole number that gives the molar mass of the compound.

Front

What is the empirical formula of C2H4O2 and C6H12O6?

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Both have the same empirical formula: CH2O.

Front

Is C6H12O6 a molecular or empirical formula?

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C6H12O6 is a molecular formula.

Front

What is the empirical formula of a compound with the formula C3H6O3?

Back

The empirical formula is C3H6O3, as it cannot be simplified further.

Tags

NGSS.MS-PS1-1

Front

What is the significance of empirical formulas in chemistry?

Back

Empirical formulas help in understanding the composition of compounds and are used in stoichiometry.