Mole

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

  A unit used to measure the amount of chemical substance
• How is the mole similar to other units of measurement?

  It measures the amount of substance like meters measure distance
• How many particles are in one mole of a substance?

  
  

  6.022 times 10 to the 23 particles
• What types of particles can be counted in moles?

  Atoms, molecules, ions, or electrons
• What is Avogadro's constant?

  The number of particles in one mole, which is 6.02 times 10 to the 23
• Why is Avogadro's constant significant in chemistry?

  It allows us to relate the mass of a substance to its relative atomic or formula mass
• What is the relative atomic mass of carbon?

  12
• What is the relative formula mass of oxygen in O2?

  32
• What is the relative formula mass of carbon dioxide (CO2)?

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

  Number of moles = mass of the element or compound / its relative formula mass
• How many moles are in 42.5 grams of ammonia (NH3) if its relative formula mass is 17?

  1. 5 moles
• What is the mass of 3 moles of carbon dioxide (CO2)?

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

  Multiply the number of moles by the mass of carbon, which is 12
• What is the mass of carbon in 3 moles of CO2?

  36 grams
• How can you find the mass of oxygen in 3 moles of CO2 if the total mass is 132 grams?

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

  It shows the ratios of moles of reactants and products
• In the reaction of magnesium with hydrochloric acid, how many moles of hydrochloric acid are needed for 2 moles of magnesium?

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


  2 moles of magnesium chloride
• How many moles of hydrogen gas are produced from 2 moles of magnesium reacting with hydrochloric acid?

  2 moles of hydrogen gas
• What is the relationship between moles, mass, and relative formula mass?

  • Number of moles = mass / relative formula mass
  • Mass = number of moles × relative formula mass
• What are the steps to calculate the mass of an element in a compound?

  1. Determine the number of moles of the compound.
  2. Multiply by the mass of the specific element.
  3. Optionally, subtract from the total mass to find the mass of other elements.
• How do chemical equations relate to moles?

  • Chemical equations represent the ratios of moles of reactants and products.
  • They help in stoichiometric calculations.