Moles and Calculations

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

  A unit to measure the amount of substance
• How many particles are in one mole of a substance?

  6.02 times 10 to the 23 particles
• What does "particles" refer to in the context of moles?

  Atoms, molecules, ions, or electrons
• If you have one mole of carbon, how many atoms are present?

  6.02 times 10 to the 23 atoms
• What is Avogadro's constant?

  6.02 times 10 to the 23 particles per mole
• Why is Avogadro's constant significant?

  It relates mass to relative atomic/formula mass
• What is the mass of one mole of carbon?

  12 grams
• What is the mass of one mole of oxygen?

  32 grams
• How much does one mole of CO2 weigh?

  44 grams
• How do you calculate the number of moles in a sample?

  Mass divided by relative formula mass
• How many moles are in 42.5 grams of ammonia?


  2.5 moles
• What is the relative formula mass (mr) of ammonia?

  17
• What is the mass of 3 moles of carbon dioxide?

  132 grams
• How do you find the mass of carbon in 3 moles of CO2?

  Multiply 3 moles by 12 grams
• What is the mass of carbon in 3 moles of CO2?

  36 grams
• How do you find the mass of oxygen in CO2?

  Subtract carbon mass from total mass
• What does a chemical equation represent in terms of moles?

  Ratios of reactants and products in moles
• If you start with 2 moles of magnesium, how many moles of hydrochloric acid do you need?

  4 moles
• How many moles of magnesium chloride are produced from 2 moles of magnesium?

  2 moles
• How many moles of hydrogen gas are produced from 2 moles of magnesium?

  2 moles