What defines Avogadro's number?

What defines Avogadro's number?

• A. 6.022 x 10²².
• B. The number of molecules in a gram of substance.
• C. 6.022 x 10²³, the number of atoms in 12g of ¹²C.
• D. The number of moles in a liter of solution.

Answer: (C)

Avogadro's number is defined as 6.022 x 10²³, which specifically represents the number of atoms, molecules, or particles in one mole of a substance. This definition is anchored in the context of carbon-12, where one mole of carbon-12, which has a mass of 12 grams, contains exactly 6.022 x 10²³ carbon atoms. This high level of precision is critical in chemistry, as it provides a standard for measuring quantities of substances. By establishing this relationship, Avogadro's number allows chemists to perform calculations involving moles and to convert between mass and the number of particles in a sample. This understanding is foundational in stoichiometry and molecular chemistry. Other options either misrepresent Avogadro's number or provide incorrect context. For instance, mentioning 6.022 x 10²² does not align with the established definition of Avogadro's number. Describing it as the number of molecules in a gram of substance lacks clarity, as the number of molecules depends on the substance's molar mass. Lastly, stating it as the number of moles in a liter of solution confuses the concept of molarity with Avogadro's number, as the latter

Avogadro's number is defined as 6.022 x 10²³, which specifically represents the number of atoms, molecules, or particles in one mole of a substance. This definition is anchored in the context of carbon-12, where one mole of carbon-12, which has a mass of 12 grams, contains exactly 6.022 x 10²³ carbon atoms. This high level of precision is critical in chemistry, as it provides a standard for measuring quantities of substances.

By establishing this relationship, Avogadro's number allows chemists to perform calculations involving moles and to convert between mass and the number of particles in a sample. This understanding is foundational in stoichiometry and molecular chemistry.

Other options either misrepresent Avogadro's number or provide incorrect context. For instance, mentioning 6.022 x 10²² does not align with the established definition of Avogadro's number. Describing it as the number of molecules in a gram of substance lacks clarity, as the number of molecules depends on the substance's molar mass. Lastly, stating it as the number of moles in a liter of solution confuses the concept of molarity with Avogadro's number, as the latter