The mole - Higher

• What is the mole in chemistry?

  The mole is the unit for amount of substance.
• How can the number of particles in a substance be found?

  Using the Avogadro constant.
• What does the mass of a product depend on in a chemical reaction?

  The mass of the limiting reactant.
• What is the symbol for the mole?

  • The symbol for the mole is mol.
• What is the definition of a mole?

  A mole contains the same number of particles as there are atoms in 12 g of carbon-12.
• What is the value of Avogadro's constant?

  1. 02 × 10²³ per mole.
• What does the mass of one mole of a substance equal for an element?

  The relative atomic mass of its formula in grams.
• What does the mass of one mole of a compound equal?

  The relative formula mass of its formula in grams.
• What is the relative atomic mass (A_r)?

  • The mean relative mass of the atoms of the different isotopes in an element.
  • It is the number of times heavier an atom is than one-twelfth of a carbon-12 atom.
• What is the relative formula mass (M_r)?

  • The sum of the relative atomic masses of the atoms in a chemical formula.
• What is the mass of 1 mole of calcium (Ca)?

  40 g.
• What is the mass of 1 mole of oxygen (O₂)?

  32 g.
• What is the mass of 1 mole of calcium carbonate (CaCO₃)?

  100 g.
• How many particles are in one mole of a substance?

  One mole contains the same number of particles as one mole of any other substance.
• What types of particles can the amount in moles apply to?

  Atoms, molecules, ions, and electrons.
• How can you calculate the number of particles in a substance?

  Using the formula: Number of particles = Avogadro constant × amount of substance in mol.
• Calculate the number of water molecules in 0.5 mol of water.

  1. 01 × 10²³ water molecules.
• How many atoms are in 3.01 × 10²³ water molecules?

  1. 03 × 10²³ atoms.
• Calculate the number of oxygen atoms in 0.5 mol of oxygen molecules (O₂).

  1. 02 × 10²³ oxygen atoms.
• What is the relationship between moles and the number of particles?

  • One mole contains 6.02 × 10²³ particles.
  • The number of particles can be calculated using the Avogadro constant and the amount of substance in moles.