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 methane and oxygen produce when they react?

  Carbon dioxide and water
• What are the reactants in the methane combustion reaction?

  Methane and oxygen
• What do we call the molecules produced in a chemical reaction?

  Products
• What does the single arrow in a chemical equation indicate?

  Reactants react completely to form products
• What is the symbol for methane in a chemical equation?

  $CH_4$
• What is the symbol for oxygen in a chemical equation?

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


  Oxygen exists as a molecule of two atoms
• What is required for a chemical equation to be balanced?

  Same total number of each atom on both sides
• How many carbon, hydrogen, and oxygen atoms are on the left side of the methane combustion equation?

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

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

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

  It would change the type of chemicals
• How do we increase the number of oxygen atoms on the left side?

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

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

  Increase the number of water molecules
• What is the process for 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 only
  5. Double-check for balance
• What is the reaction between sulfuric acid and sodium hydroxide?

  Forms sodium sulfate and water
• How many hydrogens, sulfurs, oxygens, and sodiums are on the left side of the sulfuric acid reaction?

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

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

  Sulfur and sodium
• What adjustment is made to balance sodium in the sulfuric acid reaction?

  Put a 2 in front of sodium hydroxide
• How do we fix the imbalance of hydrogens and oxygens after adjusting sodium?

  Add one more water molecule to the right
• What should you do after balancing a chemical equation?

  Double-check to see if it's balanced
• What are the key components of a balanced chemical equation?

  • Reactants on the left
  • Products on the right
  • Same number of each atom on both sides
  • Coefficients represent quantity