The Mole

• What does the term mole refer to in chemistry?

  A unit to measure the amount of substance
• How many particles are in one mole of a substance?

  $6.02 \times 10^{23}$ particles
• What does Avogadro's constant represent?

  The number of particles in one mole
• What is the relative atomic mass of carbon?

  12
• How much does one mole of carbon weigh?

  12 grams
• What is the relative formula mass of oxygen in O₂?

  32
• How much does one mole of CO₂ weigh?

  44 grams
• What is the formula to calculate the number of moles?

  Number of moles = mass / relative formula mass
• How many moles are in 42.5 grams of ammonia?

  2.5 moles
• How do you find the mass of a substance from moles?

  Multiply moles by relative formula mass
• What is the mass of 3 moles of CO₂?

  132 grams
• How do you calculate the mass of carbon in 3 moles of CO₂?

  36 grams of carbon
• What is the total mass of CO₂ if carbon weighs 36 grams?

  132 grams
• What is the composition of CO₂ in terms of elements?

  Made up of carbon and oxygen
• How can chemical equations be interpreted in terms of moles?

  As ratios of reactants and products
• How many moles of hydrochloric acid react with 2 moles of magnesium?

  4 moles of hydrochloric acid
• What do you produce when magnesium reacts with hydrochloric acid?

  Magnesium chloride and hydrogen gas
• What are the key concepts related to the mole in chemistry?

  • Mole as a unit of measurement
  • Avogadro's constant: $6.02 \times 10^{23}$ particles
  • Relative atomic/formula mass equals mass of one mole in grams
  • Formula: Number of moles = mass / relative formula mass
• How do you calculate the mass of elements in compounds?

  1. Determine the number of moles.
  2. Multiply by the relative atomic mass of the element.
  3. Subtract from total mass for other elements.
• How do chemical equations relate to moles?

  • Represent ratios of reactants and products.
  • Example: 1 mole of magnesium reacts with 2 moles of hydrochloric acid.