Chemical Equations

• What are chemical equations fundamental to?

  Chemistry
• How are chemical equations similar to a recipe?

  They describe the process of a reaction
• What do chemical equations show about a reaction?

  They show what happens to atoms
• What are the products of burning methane in oxygen?

  Carbon dioxide and water
• What are the molecules on the left side of a chemical equation called?

  Reactants
• What are the molecules on the right side of a chemical equation called?

  Products
• Why must chemical equations be balanced?

  To obey the law of conservation of mass
• What are the steps to balance a chemical equation?

  1. Write the unbalanced equation
  2. Count the number of atoms for each element
  3. Adjust coefficients to balance atoms
  4. Ensure the same number of each atom on both sides
  5. Check your work for accuracy
• How would you balance the equation for sulfuric acid reacting with sodium hydroxide?

  H₂SO₄ + 2NaOH → Na₂SO₄ + 2H₂O
• What is the formula for the reaction of magnesium and oxygen?

  2Mg + O₂ → 2MgO
• What does balancing the equation 2Mg + O₂ → 2MgO indicate?

  Two magnesium atoms react with one oxygen molecule
• Why can't you change the subscripts in a chemical formula to balance an equation?

  It changes the identity of the substance
• What is the balanced equation for the reaction of aluminum and oxygen?

  4Al + 3O₂ → 2Al₂O₃
• What is the significance of the coefficients in a balanced equation?

  They indicate the number of molecules involved
• If you have the equation 2H₂ + O₂ → 2H₂O, how many water molecules are produced?


  2 water molecules
• What are the key rules for balancing chemical equations?

  • Use coefficients to balance atoms
  • Never change subscripts
  • Balance one element at a time
  • Check that all atoms are balanced
  • Ensure the same number of each atom on both sides
• What is the formula for the reaction of sodium and chlorine?

  2Na + Cl₂ → 2NaCl
• What does the equation 2Na + Cl₂ → 2NaCl represent?

  Two sodium atoms react with one chlorine molecule
• How do you know if a chemical equation is balanced?

  Each side has the same number of atoms
• What is the balanced equation for the reaction of iron and oxygen?

  4Fe + 3O₂ → 2Fe₂O₃
• Why is it important to balance chemical equations in reactions?

  It ensures mass is conserved in reactions
• If you have the equation 2H₂ + O₂ → 2H₂O, how many hydrogen molecules are needed?

  2 hydrogen molecules
• What happens if a chemical equation is not balanced?

  It violates the law of conservation of mass
• What is the balanced equation for the reaction of calcium and water?

  Ca + 2H₂O → Ca(OH)₂ + H₂
• What does the equation Ca + 2H₂O → Ca(OH)₂ + H₂ indicate?

  Calcium reacts with water to produce hydroxide
• How can you verify that a chemical equation is balanced?

  Count the number of atoms for each element
• What is the balanced equation for the reaction of potassium and bromine?

  2K + Br₂ → 2KBr
• What does the equation 2K + Br₂ → 2KBr represent?

  Two potassium atoms react with one bromine molecule
• What is the importance of coefficients in a balanced equation?

  They indicate the ratio of reactants to products
• What is the balanced equation for the reaction of zinc and hydrochloric acid?

  Zn + 2HCl → ZnCl₂ + H₂
• What does the equation Zn + 2HCl → ZnCl₂ + H₂ indicate?

  Zinc reacts with hydrochloric acid to produce hydrogen
• How do you know if the equation Zn + 2HCl → ZnCl₂ + H₂ is balanced?

  Each side has the same number of atoms
• What is the balanced equation for the reaction of copper and sulfuric acid?

  Cu + H₂SO₄ → CuSO₄ + H₂
• What does the equation Cu + H₂SO₄ → CuSO₄ + H₂ represent?

  Copper reacts with sulfuric acid to produce hydrogen
• What is the significance of balancing equations in chemical reactions?

  It ensures mass is conserved in reactions
• What is the balanced equation for the reaction of lead and nitric acid?

  Pb + 4HNO₃ → Pb(NO₃)₂ + 2H₂O + 2NO₂
• What does the equation Pb + 4HNO₃ → Pb(NO₃)₂ + 2H₂O + 2NO₂ indicate?

  Lead reacts with nitric acid to produce nitrogen dioxide
• How can you verify that the equation Pb + 4HNO₃ → Pb(NO₃)₂ + 2H₂O + 2NO₂ is balanced?

  Count the number of atoms for each element
• What is the balanced equation for the reaction of silver and nitric acid?

  Ag + 2HNO₃ → AgNO₃ + H₂
• What does the equation Ag + 2HNO₃ → AgNO₃ + H₂ represent?

  Silver reacts with nitric acid to produce hydrogen