Calculating Moles of an Element

• What is the main topic of the video?

  Calculating the number of moles of an element
• What is relative atomic mass?

  • Mass of a single atom of an element
  • Calculated from average masses of isotopes weighted for their abundance
  • Found on the periodic table
• What is the relative atomic mass of carbon?

  12
• What is the relative atomic mass of oxygen?

  16
• Why is the mole concept useful in chemistry?

  It helps calculate how many atoms of a substance are present in a chemical reaction
• How is one mole defined in terms of mass?

  One mole corresponds to the relative atomic mass of an element in grams
• How do you calculate the number of moles of an element?

  • Use the equation: Number of moles = mass in grams / relative atomic mass
• If you have 48 g of magnesium, how many moles do you have?

  2 moles
• How many moles are in 120 g of calcium?

  3 moles
• How many moles are in 252 g of iron?

  4.5 moles
• How many moles are in 4,064 g of sulfur?

  127 moles