Empirical vs molecular formula notes

What is an empirical formula?

An empirical formula shows the simplest whole-number ratio of atoms in a compound.

Example of empirical formula for glucose.

The empirical formula for glucose (C₆H₁₂O₆) is CH₂O.

What is a molecular formula?

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

True or false: CH₂O is a molecular formula.

False, because CH₂O is an empirical formula, not a molecular formula.

Difference between empirical and molecular formulas.

Empirical formulas show ratios; molecular formulas show actual numbers of atoms.

Fill in the blank: C₃H₈ is a _____ formula.

C₃H₈ is a molecular formula.

How to derive a molecular formula?

Multiply the empirical formula by a whole number to get the molecular formula.

Question: What information does the empirical formula provide?

It gives the simplest ratio of elements present in a compound.

True or false: The empirical formula can be the same for different compounds.

True, different compounds can share the same empirical formula.

Example of substances with the same empirical formula.

C₂H₆ and C₄H₁₂ both have the empirical formula CH₃.

What is the empirical formula of benzene?

The empirical formula of benzene (C₆H₆) is CH.

Question: Why is the molecular formula significant?

It provides specific information about the number of atoms in a molecule.

Fill in the blank: The empirical formula for butane is _____.

C₂H₅.

How can you identify empirical formulas from molecular formulas?

Divide the subscripts in the molecular formula by their greatest common divisor.

Question: What does the 'C' in CH₄ represent?

The 'C' represents carbon atoms in the molecular formula of methane.

True or false: Molecular formulas can be more complex than empirical formulas.

True, they can indicate more specific combinations of elements.