Why is the concept of moles important in chemistry?

• A. It is used to measure the temperature of chemical reactions.
• B. It helps determine the color changes in chemical solutions.
• C. It allows chemists to count atoms, molecules, or ions by relating mass to number of particles.
• D. It is necessary for calculating the pressure of gases in a container.

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 a typical laboratory setting.
2. Recognize that the mole is a fundamental unit in chemistry that provides a bridge between the microscopic world (atoms, molecules) and the macroscopic world (grams, liters).
3. Know that one mole corresponds to exactly \$6.022 \times 10^{23}$ particles (Avogadro's number), allowing chemists to count particles by weighing substances.
4. Realize that using moles enables chemists to relate the mass of a substance to the number of particles it contains, which is essential for stoichiometric calculations in chemical reactions.
5. Conclude that the mole concept is important because it allows chemists to quantify and compare amounts of substances in a meaningful and practical way, rather than measuring unrelated properties like temperature or color.