1. Why is the mole used as a unit in chemistry?

• A. To determine the color of a compound
• B. To measure the volume of a solution
• C. To count large numbers of atoms, molecules, or ions using a manageable unit
• D. To calculate the boiling point of a substance

Answer: (C)

Verified step by step guidance

1. Understand that atoms, molecules, and ions are extremely small and numerous, making it impractical to count them individually in chemical reactions or measurements.
2. Recognize that the mole is a unit that chemists use to count these particles in a manageable way, similar to how a dozen is used to count 12 items.
3. Know that one mole corresponds to Avogadro's number, which is approximately \$6.022 \times 10^{23}$ particles, providing a bridge between the microscopic scale and the macroscopic scale.
4. Realize that using the mole allows chemists to relate the mass of a substance to the number of particles it contains, facilitating calculations in chemical equations and reactions.
5. Conclude that the mole is not used to determine color, volume, or boiling point directly, but rather to count large numbers of atoms, molecules, or ions efficiently.