LT 3.2 - Empirical/Molecular Formulas & % Composition

Front

What is an Empirical Formula?

Back

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

Front

What is a Molecular Formula?

Back

The 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

To calculate the molar mass, sum the atomic masses of all the atoms in the molecular formula.

Front

What is the molar mass of NaCl?

Back

58.443 g/mol.

Front

What is the empirical formula of C10H8?

Back

C5H4.

Front

What is the relationship between empirical and molecular formulas?

Back

The empirical formula is a simplified version of the molecular formula, representing the lowest whole number ratio of elements.

Front

What is the molar mass of NaOH?

Back

40 g/mol.

Front

What does atomic mass represent?

Back

Atomic mass represents the mass of an atom, typically measured in atomic mass units (amu), and is numerically equivalent to the molar mass in grams per mole.

Front

What is the significance of % composition in a compound?

Back

% composition indicates the percentage by mass of each element in a compound.

Front

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

Back

To find % composition, divide the mass of the element in one mole of the compound by the molar mass of the compound, then multiply by 100.