One mole is not called anything else other than a mole, but it is a fundamental unit in chemistry used to measure the amount of a substance. It is defined based on the number of elementary entities that it contains.
Understanding the Mole
The mole is defined as the amount (mass) of a substance that contains the same number of elementary entities (atoms, molecules or ions) as there are atoms in 12.000 g of isotope of carbon. This definition links the mole to the atomic mass scale.
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This concept of counting atoms, molecules, or ions is essential in chemical reactions.
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One mole of any substance contains a fixed number of entities which is equal to Avogadro’s number (NA).
Avogadro's Number
Avogadro's number (NA) represents the number of particles present in one mole of a substance.
- Value: NA = 6.023 x 10^23.
- This number is a universal constant used in chemistry to relate macroscopic quantities with microscopic particles.
Key Takeaways
- A mole is a unit of amount of substance.
- It is based on the number of particles, not mass directly.
- One mole always contains Avogadro's number (6.023 x 10^23) of entities.
- The mole is a crucial concept for stoichiometry, or the quantitative study of chemical reactions.
Practical Insight
The mole concept allows chemists to:
- Convert mass into the number of atoms or molecules.
- Predict the amount of reactants needed for a complete reaction.
- Determine the yields of products in a reaction.
