One mole of a substance is defined as
Correct answer: A. the amount containing as many particles as there are atoms in 12 g of carbon 12
- A. the amount containing as many particles as there are atoms in 12 g of carbon 12
- B. one gram of the substance
- C. the mass of one molecule of the substance
- D. the volume occupied by one gram of a gas
Explanation
The mole is a counting unit fixed by reference to 12 g of carbon 12, which is why the molar mass of any substance in grams contains exactly Avogadro's number of particles. Defining it by mass alone would be meaningless, since one gram of hydrogen and one gram of lead contain hugely different numbers of atoms. The mole is what lets a chemist count particles by weighing.
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About Moles and Avogadro's Number
The mole connects the microscopic number of particles with measurable mass, using Avogadro's number, 6.022 × 10²³ particles per mole. Questions involve molar mass, conversion between mass, moles and particles, percentage composition, empirical and molecular formulas, and distinguishing atoms, molecules, ions and formula units.
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