Calculating Moles of a Compound

• What is a mole in chemistry?

  A mole is a very large number used to quantify substances.
• How can the number of moles of an element be calculated?

  The number of moles is calculated by dividing the mass in grams by the relative atomic mass.
• What is the equation for calculating the number of moles of a compound?

  • Number of moles = mass in grams / relative formula mass (Mr)
• What is relative formula mass?

  Relative formula mass is the sum of the relative atomic masses of all atoms in a compound.
• What does the symbol 'M' represent in chemistry?

  'M' represents relative formula mass.
• Does relative formula mass have units?

  No, relative formula mass has no unit.
• How do you calculate the relative formula mass of a compound?

  1. Identify the number of each type of atom in the compound.
  2. Multiply the number of atoms by their respective relative atomic masses.
  3. Sum all the values to get the relative formula mass.
• How do you calculate the number of moles of calcium carbonate given its mass?

  Divide the mass in grams by the relative formula mass of calcium carbonate.
• What is the relative atomic mass of calcium?

  40
• What is the relative atomic mass of carbon?

  12
• What is the relative atomic mass of oxygen?

  16
• How do you find the number of moles of magnesium chloride from its mass?

  Divide the mass in grams by the relative formula mass of magnesium chloride.
• What is the formula for magnesium chloride?

  MgCl₂
• What is the relative formula mass of magnesium chloride?

  95
• How do you calculate the number of moles of lithium sulfate given its mass?

  Divide the mass in grams by the relative formula mass of lithium sulfate.
• What is the formula for lithium sulfate?

  Li₂SO₄
• What is the relative formula mass of lithium sulfate?

  110
• How do you calculate the number of moles of barium hydroxide given its mass?

  Divide the mass in grams by the relative formula mass of barium hydroxide.
• What is the formula for barium hydroxide?

  Ba(OH)₂
• What is the relative atomic mass of barium?

  137
• What is the relative atomic mass of hydrogen?

  1
• What is the relative formula mass of barium hydroxide?

  43
• How many moles of barium hydroxide are in 64.5 grams?

  1.5 moles