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The molecular formula represents the number and types of atoms in a molecule. For instance, the molecular formula for Naproxen is \(\text{C}_{14}\text{H}_{14}\text{O}_{3}\). This means one molecule of Naproxen consists of:

• 14 Carbon (C) atoms
• 14 Hydrogen (H) atoms
• 3 Oxygen (O) atoms

Understanding the molecular formula is crucial because it helps identify how many moles of each atom are present in a given amount of substance. This forms the basis for calculating moles of individual elements in a compound.

To calculate moles of atoms within a compound, you need the molecular formula and the number of moles of the compound. For example:

• Given \(\text{C}_{14}\text{H}_{14}\text{O}_{3}\), each molecule contains 14 Carbon atoms, 14 Hydrogen atoms, and 3 Oxygen atoms.
• The formula to calculate moles of a specific atom is:
  \(\text{Moles of element} = \text{Moles of compound} \times \text{Number of that element in one molecule}\)
• For question (a), to find moles of \(\text{C}\) in 2.30 moles of Naproxen:
  \(\text{Moles of C} = 2.30 \times 14 = 32.2 \text{ moles of C}\)
• For question (b), to find moles of \(\text{H}\) in 0.444 moles of Naproxen:
  \(\text{Moles of H} = 0.444 \times 14 = 6.216 \text{ moles of H}\)
• For question (c), to find moles of \(\text{O}\) in 0.0765 moles of Naproxen:
  \(\text{Moles of O} = 0.0765 \times 3 = 0.2295 \text{ moles of O}\)

This approach allows us to determine the exact amount of each atom in a specific quantity of a compound.

Stoichiometry involves calculations of the quantities of reactants and products in chemical reactions. It relies on the conservation of mass and energy, ensuring the total mass and number of atoms remain constant during the reaction. Here's why stoichiometry is essential:

• It allows the calculation of how much of each reactant is needed to form a product.
• It can predict the amount of product formed in a reaction.
• Accurate stoichiometric calculations ensure that reactions are efficient and reduce waste.

When using stoichiometry, understanding the molecular formula and moles of atoms aids in precise measurements. For example, knowing that Naproxen has \(\text{C}_{14}\text{H}_{14}\text{O}_{3}\) helps in determining the proportional amounts of reactants needed in a reaction producing Naproxen. Accurate stoichiometric calculations pave the way for successful chemical synthesis and industrial applications. By mastering these calculations, you can effectively balance chemical equations and optimize reactions.