The mole concept is a fundamental concept in chemistry that provides a convenient way to express amounts of reactants and products in chemical reactions. One mole of any substance contains Avogadro's number ($6.022 \times 10^{23}$) of particles (atoms, molecules, ions, etc.). The molar mass of a substance is the mass of one mole of that substance, usually expressed in grams per mole (g/mol) and is numerically equal to the atomic or molecular weight in atomic mass units (amu). Mastering mole conversions is essential for stoichiometry and quantitative analysis.
These practice problems will test your understanding of how to convert between mass, moles, and the number of particles. Make sure you pay attention to the units and use the correct conversion factors!
Match each term with its correct definition:
| Term | Definition |
|---|---|
| 1. Mole | A. The mass of one mole of a substance |
| 2. Avogadro's Number | B. $6.022 \times 10^{23}$ particles |
| 3. Molar Mass | C. The SI unit for amount of substance |
| 4. Empirical Formula | D. The simplest whole number ratio of atoms in a compound |
| 5. Molecular Formula | E. The actual number of atoms of each element in a molecule |
(Answers: 1-C, 2-B, 3-A, 4-D, 5-E)
Complete the following paragraph using the words provided: moles, molar mass, Avogadro's number, grams, particles.
To convert from mass in __________ to __________ , you need to use the __________. This conversion factor relates the mass of a substance to the amount of substance. To convert from moles to the number of __________ you use __________.
(Answers: grams, moles, molar mass, particles, Avogadro's number)
Imagine you have two beakers, one containing 1 mole of water ($H_2O$) and the other containing 1 mole of glucose ($C_6H_{12}O_6$). Which beaker contains more molecules? Explain your answer.
(Answer: Both beakers contain the same number of molecules because they both contain 1 mole of substance. One mole always contains Avogadro's number of particles, regardless of the substance.)
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