Algonquin College Health Program Assessment (AC-HPAT) Practice Exam

Which of the following best describes the relationship between grams and moles?

1. Grams measure volume, while moles measure mass

2. Grams measure mass, while moles measure quantity of particles

3. Both grams and moles measure mass

4. Moles measure temperature, grams measure pressure

The correct answer is: Grams measure mass, while moles measure quantity of particles

The relationship between grams and moles is centered around how substances are quantified in chemistry. Grams measure the mass of a substance, providing a direct indication of the amount of material present. In contrast, moles serve as a way to quantify the number of particles, such as atoms or molecules, in that mass. This relationship is fundamental in stoichiometry, as it allows chemists to convert between the mass of a substance (expressed in grams) and the amount of substance in terms of the number of entities (expressed in moles) using the substance's molar mass. For example, knowing the molar mass of a substance allows one to determine how many grams correspond to a certain number of moles, facilitating calculations that involve chemical reactions. Thus, while grams and moles both serve distinct purposes in measuring substances, their definitions align closely with mass and the quantity of particles, respectively. This foundational understanding is crucial for accurate measurements and conversions in chemical calculations.