Balancing Chemical Equations

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

  Balance chemical equations
• Why do students find balancing chemical equations tricky?

  They may not understand the method to balance them
• What does a chemical formula represent?

  The composition of a compound
• What do capital letters in a chemical formula indicate?

  They represent elements
• How many elements are in sodium carbonate?

  Three elements
• What does the small number next to an element in a chemical formula indicate?

  The number of atoms of that element
• How many sodium atoms are in sodium carbonate?

  Two sodium atoms
• How many carbon atoms are in sodium carbonate?

  One carbon atom
• How many oxygen atoms are in sodium carbonate?

  Three oxygen atoms
• What is one of the most important rules in chemistry regarding chemical formulas?

  You cannot change the small numbers in a chemical formula
• What does placing a large number in front of a chemical formula indicate?

  It indicates the number of molecules of that compound
• What does the equation "calcium + chlorine makes calcium chloride" represent?

  A balanced chemical equation
• How can you tell if a chemical equation is balanced?

  The number of atoms of each element is the same on both sides
• In the equation "sodium + iodine makes sodium iodide," how many sodium atoms are on the left side?

  One sodium atom
• How many iodine atoms are on the left side of the equation "sodium + iodine makes sodium iodide"?

  Two iodine atoms
• What do you need to do to balance the iodine atoms in the equation "sodium + iodine makes sodium iodide"?

  Add a large number in front of sodium iodide
• After balancing the iodine in the equation, what happens to the sodium atoms?

  There are now two sodium atoms on the right side
• How do you balance the sodium atoms after adjusting the iodine in the equation?

  Add a large number in front of sodium on the left side
• What is the process to balance the equation "calcium oxide + hydrochloric acid produces calcium chloride + water"?

  • Count atoms on both sides
  • Balance calcium (1 on each side)
  • Balance oxygen (1 on each side)
  • Balance hydrogen (1 on left, 2 on right; add 2 in front of hydrochloric acid)
  • Balance chlorine (1 on left, 2 on right; now balanced with hydrogen
• How do you balance the equation "iron oxide + carbon monoxide produces iron + carbon dioxide"?

  • Count atoms on both sides
  • Balance iron (2 on each side)
  • Balance carbon (3 needed on right; add 3 in front of carbon monoxide)
  • Balance oxygen (6 on each side)
• Where can you find more questions on balancing chemical equations?

  In the revision workbook
• What should you be able to do after watching the video?

  Balance chemical equations