Avogadro’s Number

Related Examples and Practice Problems

Additional Worked Out Examples/ Practice

  • Identifying classification types: Differentiation between elements, compounds or mixtures and homogeneous and heterogenous mixtures

  • Separation techniques: Selected and explaining limitation of appropriate separation

  • Relating Properties to Composition: Predicting classification based on descriptive properties

    and more …

Topic Summary & Highlights
and Help Videos

Core Concept

Avogadro's number is defined as 6.022 × 10²³ of particles (atoms, molecules, ions, etc.) present in one mole of a substance. It is usually denoted by the symbol "Nₐ".

Practice Tips

  • Memorize Common Ions: Focus on learning the common polyatomic ions, charges, and patterns.

  • Roman Numerals for Transition Metals: Practice associating transition metals with their possible charges.

  • Cross-Method for Formulas: To determine the correct formula, use the “criss-cross” method to balance charges between cations and anions.

Topic Overview Podcast

Topic Related Resources

 LABORATORY 
 DEMONSTRATIONS 
 ACTIVITIES 
 VIRTUAL SIMULATIONS 

Core Concept

Avogadro's number is defined as 6.022 × 10²³ of particles (atoms, molecules, ions, etc.) present in one mole of a substance. It is usually denoted by the symbol "Nₐ".

  1. Calculation: To calculate the number of particles in a sample, multiply the amount of the substance in moles by Avogadro's number. For example, if you have 2 moles of water, the number of water molecules present would be 2 × 6.022 × 10²³ = 1.2044 × 10²⁴ molecules.

  2. Relationship to molar mass: Avogadro's number is also related to the molar mass of a substance. The molar mass is the mass of one mole of a substance in grams. The molar mass of a substance can be calculated by dividing the mass of a sample by the number of moles present, which can then be used to calculate the number of particles using Avogadro's number.

  3. Importance: Avogadro's number is a crucial concept in many areas of chemistry, including stoichiometry, gas laws, and thermodynamics. It provides a way to relate the number of particles in a sample to its macroscopic properties, such as volume and pressure.

  4. Units: Avogadro's number has units of particles per mole (or molecules per mole).

  5. Experimental determination: The value of Avogadro's number can be determined experimentally by a variety of methods, including X-ray crystallography, electron microscopy, and measurements of the density and viscosity of gases.

  6. Use in the mole concept: Avogadro's number is an integral part of the mole concept, which is used to relate the number of particles in a sample to its mass and volume.

  7. Applications: Avogadro's number is used in many applications in chemistry, including in the calculation of reaction stoichiometry, the determination of molecular weight, and the analysis of gas properties.

Video Resources