moles of a compound

• What is the main topic of this video?

  Calculating the number of moles of a compound
• What is a mole in chemistry?

  A very large number of particles
• How do you calculate the number of moles from mass?

  Mass in grams divided by relative atomic mass
• What is relative formula mass?

  Sum of relative atomic masses in a compound
• What is the relative formula mass of carbon dioxide?

  44
• How is relative formula mass denoted?

  With the symbol M
• What is the formula to calculate the number of moles of a compound?

  Number of moles = mass in grams / relative formula mass
• How does the equation for moles of a compound differ from that of an element?

  It divides by relative formula mass instead
• What is the relative formula mass of calcium carbonate?

  100
• How many moles are in 300 g of calcium carbonate?

  3 moles
• What is the formula for magnesium chloride?

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

  95
• How many moles are in 380 g of magnesium chloride?

  4 moles
• What is the formula for lithium sulfate?

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

  110
• How many moles are in 990 g of lithium sulfate?


  9 moles
• What is the formula for barium hydroxide?

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

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

  1.5 moles
• What is the process to calculate the number of moles of a compound?

  1. Determine the relative formula mass (Mr).
  2. Use the equation:

  • Number of moles = mass in grams / Mr.

  1. Substitute the values to find the number of moles.
• What are the steps to find the relative formula mass of a compound?

  1. Identify the elements in the compound.
  2. Find the relative atomic mass of each element.
  3. Multiply by the number of atoms of each element.
  4. Sum all the values to get the relative formula mass.