The Mole and Equations

• What is the term used to describe an amount of substance?

  Mole
• What is the Avogadro constant?

  6.02 x 10^23
• What does one mole of a substance contain?

  6.02 x 10^23 particles
• What types of particles can be in a mole?

  Atoms, molecules, ions, or electrons
• What is the relationship between the mass of a mole and relative atomic mass?

  Mass in grams equals relative atomic mass
• What is the relative atomic mass of carbon?

  12
• What is the relative formula mass of nitrogen gas (N₂)?

  28
• What is the relative formula mass of carbon dioxide (CO₂)?

  44
• How much does one mole of carbon weigh?

  12 g
• How much does one mole of N₂ weigh?

  28 g
• How much does one mole of CO₂ weigh?

  44 g
• What does 12 g of carbon contain in terms of particles?

  One mole or 6.02 x 10²³ particles
• What is the formula to find the number of moles in a given mass?

  Number of moles = mass in g / Mr
• How many moles are in 66 g of carbon dioxide (CO₂)?

  1.5 mol
• What mass of carbon is there in 4 moles of carbon dioxide?

  48 g
• What do the numbers in front of chemical formulas in balanced equations represent?

  How many moles of each substance
• What is the first step to balance equations using reacting masses?

  Divide mass by relative formula mass
• What do you do after finding the number of moles of each substance?

  Divide by the smallest number of moles
• What do you do if any of the mole numbers are not whole numbers?

  Multiply all by the same amount
• What is the balanced symbol equation for the reaction of zinc oxide with carbon?

  2ZnO + C → CO₂ + 2Zn
• How many moles of zinc oxide (ZnO) are in 8.1 g?

  0.10 mol
• How many moles of carbon dioxide (CO₂) are produced from 2.2 g?

  0.050 mol
• How many moles of carbon (C) are in 0.60 g?

  0.050 mol
• What is the relationship between the mass of reactants and products in a chemical reaction?

  Mass of reactants equals mass of products
• What are the steps to balance a chemical equation using reacting masses?

  1. Divide mass by relative formula mass
  2. Divide by the smallest number of moles
  3. Multiply to get whole numbers if needed
  4. Write the balanced symbol equation
• How do you calculate the mass of a substance from moles?

  • Use the formula: mass = number of moles x Mr
  • Rearrange the formula triangle as needed
• What is the process to find the number of moles from a given mass?

  • Use the formula: number of moles = mass / Mr
  • Calculate the relative formula mass first
• What is the significance of the Avogadro constant in chemistry?

  • Defines the number of particles in a mole
  • Essential for converting between mass and moles