Calculating moles of an element

• What should you be able to calculate by the end of this video?

  The number of moles of an element
• What is the focus of the upcoming videos?

  Using maths for chemistry calculations
• What does relative atomic mass represent?

  The mass of a single atom of an element
• How is relative atomic mass calculated?

  From average masses of isotopes weighted by abundance
• Where can relative atomic masses be found?

  On the periodic table
• What is the relative atomic mass of carbon?

  12
• What is the relative atomic mass of oxygen?

  16
• What does the term "mole" refer to in chemistry?

  A very large number of particles
• How many grams of carbon correspond to one mole?

  12 grams
• How many grams of oxygen correspond to one mole?

  16 grams
• What is the significance of the mole in chemistry?

  It allows calculation of atoms in reactions
• How do you calculate the number of moles from mass?

  Divide mass in grams by relative atomic mass
• What is the number of moles in 48 grams of magnesium?

  2 moles
• How do you find the number of moles of calcium from 120 grams?

  3 moles
• What is the number of moles in 252 grams of iron?

  1. 5 moles
• How many moles are in 4,064 grams of sulfur?

  127 moles
• What is the equation to calculate the number of moles?

  • Number of moles = mass (g) / relative atomic mass
• What are the steps to calculate moles from mass?

  1. Identify the mass in grams.
  2. Find the relative atomic mass.
  3. Use the equation: moles = mass / atomic mass.
• What are the relative atomic masses of common elements mentioned?

  • Carbon: 12
  • Oxygen: 16
  • Magnesium: 24
  • Calcium: 40
  • Iron: 56
  • Sulfur: 32