U6 Day 3 - Empirical and Molecular Formulas

Front

What is the empirical formula?

Back

The empirical formula is the formula that shows the simplest whole-number ratio of elements in a compound.

Front

What is the molecular formula?

Back

The molecular formula shows the actual number and kinds of atoms present in one molecule of a compound.

Front

How do you determine the empirical formula from percent composition?

Back

Convert the percent composition to grams, then to moles, and find the simplest whole-number ratio.

Front

What is the relationship between empirical and molecular formulas?

Back

The molecular formula is a multiple of the empirical formula.

Front

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

Back

Mg3N2

Front

What is the molecular formula for glycerol with a molar mass of 92.09 g/mol and percent composition of 39.12% C, 8.75% H, and 51.12% O?

Back

C3H8O3

Front

If a compound has an empirical formula of K2SO4 and a molecular mass of 696g, what is its molecular formula?

Back

K8S4O16

Front

What is the percent composition of a compound?

Back

Percent composition is the percentage by mass of each element in a compound.

Front

How do you calculate the percent composition of an element in a compound?

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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 formula for calculating molar mass?

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Molar mass = sum of the atomic masses of all atoms in the formula.