quantitative chemistry

• What is relative formula mass?

  Sum of atomic masses in a molecular formula
• How do you calculate the relative formula mass of MgCl₂?

  Add atomic mass of Mg and Cl
• What is the atomic mass of magnesium?

  24
• What is the atomic mass of chlorine?

  35.5
• How many atoms of chlorine are in MgCl₂?

  Two
• What is a mole?

  Amount of substance containing $6.02 \times 10^{23}$ particles
• What is Avogadro's number?

  $6.02 \times 10^{23}$
• How does a mole relate to atomic mass?

  One mole of an element weighs its atomic mass in grams
• What is the mole equation?

  Number of moles = mass in grams / relative atomic mass
• How can you remember the mole equation using a triangle?

  • Mass on top
  • Moles and relative mass at the bottom
  • "Mr mole with a mass on his head"
• What is a key fact about mass in chemical reactions?

  Mass is always conserved in a reaction
• What is the concentration equation?

  Concentration = mass / volume
• What are the units for concentration?

  g/dm³ or g/cm³
• What is a limiting reactant?

  The reactant that runs out first in a reaction
• How does the limiting reactant affect product yield?

  It determines the amount of product produced
• What is the process for balancing chemical equations?

  1. Write down individual atoms on both sides
  2. Adjust coefficients to balance each atom
  3. Ensure all atoms match on both sides
• How do you balance the equation NaO₃ → NaCl + O₂?

  Adjust coefficients for Na, Cl, and O
• Why is it important to balance chemical equations?

  To ensure conservation of mass
• What is the final balanced equation for NaO₃ → NaCl + O₂?

  2NaO₃ → 2NaCl + 3O₂
• What is the next topic after quantitative chemistry?

  Chemical changes