Balancing equations

• What is necessary to show what happens in a chemical reaction?

  Understanding chemical equations
• What is one way to show a chemical reaction?

  Using a word equation
• What do we call the substances that react in a chemical equation?

  Reactants
• What are the substances produced in a chemical reaction called?

  Products
• What symbol is used to show that reactants form products in a chemical equation?

  A single arrow
• What is the chemical symbol for methane?

  $CH_4$
• What is the chemical symbol for oxygen as a molecule?

  $O_2$
• Why do we write $O_2$ instead of $O$ in chemical equations?


  Because oxygen exists as a diatomic molecule
• What must be true for a chemical equation to be balanced?

  Same total number of each type of atom
• How many carbon, hydrogen, and oxygen atoms are on the left side of the equation for methane burning?

  1 carbon, 4 hydrogens, 2 oxygens
• How many carbon, hydrogen, and oxygen atoms are on the right side of the equation for methane burning?

  1 carbon, 2 hydrogens, 3 oxygens
• What is the first rule of balancing chemical equations?

  Do not change the small numbers
• Why can't we change the small numbers in a chemical equation?

  It changes the type of chemicals involved
• How do we increase the number of oxygen atoms on the left side of the equation?

  Put a 2 in front of $O_2$
• What happens if we try to use one and a half molecules of oxygen when balancing?

  We must round up to two molecules
• How do we balance the number of hydrogens on the right side of the equation?

  By increasing the number of water molecules
• What is the process of balancing chemical equations?

  1. Count atoms on both sides
  2. Adjust coefficients (big numbers) to balance
  3. Keep small numbers unchanged
  4. Ensure whole numbers are used
  5. Double-check for balance
• What is the chemical equation for sulfuric acid reacting with sodium hydroxide?

  $H_2SO_4 +$$NaOH \rightarrow Na_2SO_4 +$$H_2O$
• How many hydrogens, sulfur, oxygens, and sodiums are on the left side of the sulfuric acid equation?

  3 hydrogens, 1 sulfur, 5 oxygens, 1 sodium
• How many hydrogens, sulfur, oxygens, and sodiums are on the right side of the sulfuric acid equation?

  2 hydrogens, 1 sulfur, 5 oxygens, 2 sodiums
• Which elements should be balanced first in the sulfuric acid equation?

  Sulfur and sodium
• How do we fix the sodium imbalance in the sulfuric acid equation?

  By putting a 2 in front of sodium hydroxide
• What do we need to balance after adjusting sodium in the sulfuric acid equation?

  Two more hydrogens and one more oxygen
• How do we fix the hydrogen and oxygen imbalance in the sulfuric acid equation?

  By adding one more water molecule
• What should you do after balancing a chemical equation?

  Double-check to see if it's balanced
• What are the key steps in balancing a chemical equation?

  • Count atoms on both sides
  • Adjust coefficients to balance
  • Keep small numbers unchanged
  • Use whole numbers only
  • Verify the final balance