the moles

• What is the mole in chemistry?

  A very big number, $6.02 \times 10^{23}$
• What does a mole represent in terms of carbon atoms?

  It represents the number of carbon atoms in 12 grams
• How many carbon atoms are in 12 grams of carbon?

  $6.02 \times 10^{23}$ carbon atoms
• How many moles are in 12 grams of carbon?

  1 mole
• How many moles are in 120 grams of carbon?

  10 moles
• How many moles are in 1000 grams of carbon?

  83.3 moles
• What is the mass of a mole of magnesium?

  24 grams
• How many moles are in 500 grams of magnesium?

  20.8 moles
• How many moles are in 1 gram of helium?

  0.25 moles
• Why do chemists prefer to deal with moles instead of mass?

  Because moles represent the number of atoms involved
• What is the relationship between molar mass and relative atomic mass?

  • Molar mass is the relative atomic mass in grams
  • Example: Carbon's molar mass is 12 grams
• What is the molar mass of carbon dioxide?

  48 grams
• What is the molar mass of sodium chloride?

  58.5 grams
• How many moles are in 1 gram of lithium?

  0.14 moles
• How many moles are in 1 gram of iron?

  0.014 moles
• How can you calculate the number of moles from mass?

  • Use the triangle:
  • $m$ = mass
  • $n$ = number of moles
  • $M$ = molar mass
  • Formula: $n =$$\frac{m}{M}$
• What should you do with the relative atomic mass when calculating moles?

  Use it from a periodic table
• To what decimal place should answers be given in calculations?

  One decimal place
• What is the mass of a mole of helium?

  4 grams
• What are the key concepts related to the mole in chemistry?

  • A mole is $6.02 \times 10^{23}$ particles
  • Represents the number of atoms in 12 grams of carbon
  • Molar mass is the mass of one mole in grams