Balancing equations

• What are the two main ways to represent chemical reactions?

  • Word equations
  • Symbol equations
• What is a word equation?

  A word equation represents a chemical reaction using the names of the reactants and products.
• What is a symbol equation?

  A symbol equation represents a chemical reaction using the chemical symbols of each molecule involved.
• What is meant by reactants and products in a chemical reaction?

  • Reactants: Substances that react together at the start of a chemical reaction
  • Products: Substances that are formed as a result of the chemical reaction
• What type of molecule is methane?

  $CH_4$
• What type of molecule is oxygen?

  $O_2$
• What type of molecule is carbon dioxide?

  $CO_2$
• What type of molecule is water?

  $H_2O$
• Why is it important to balance chemical equations?

  • To ensure that the total number of each type of atom is the same on both sides of the equation
  • To represent the conservation of mass during a chemical reaction
• What must be equal on both sides of a balanced chemical equation?

  The total number of each type of atom.
• How is the conservation of mass represented in a balanced chemical equation?

  By having the same total number of each type of atom on both sides.
• What is a chemical equilibrium?

  A state in a chemical reaction where the rate of the forward reaction equals the rate of the reverse reaction.
• What must you change to balance a chemical equation?

  The coefficients in front of the chemical formulas.
• What cannot be changed when balancing a chemical equation?

  The subscripts in the chemical formulas.
• Why can't subscripts in chemical formulas be changed when balancing equations?

  Because changing subscripts alters the type of chemical involved.
• What does the coefficient in front of a chemical formula represent?

  The number of molecules or atoms of that substance involved in the reaction.
• What is the process of balancing chemical equations?

  Adjusting the coefficients of reactants and products to ensure equal numbers of each type of atom on both sides of the reaction.
• What is the first rule of balancing chemical equations?

  Subscripts cannot be changed as they define the type of chemical.
• What number can be changed when balancing chemical equations?

  The coefficients in front of the chemical formulas.
• Why can't fractions be used as coefficients in balanced chemical equations?

  Because coefficients must represent whole numbers to indicate the number of molecules involved.
• What type of numbers must be used as coefficients in balanced chemical equations?

  Whole numbers.
• How do you increase the number of oxygen atoms on the left side of a chemical equation?

  Increase the coefficient of oxygen molecules $O_2.$
• How do you increase the number of hydrogen atoms on the right side of a chemical equation?

  Increase the coefficient of water molecules $H_2O.$
• What common problem arises when balancing chemical equations regarding coefficients?

  The need to use whole numbers instead of fractions.
• What should you do if you encounter a need for fractional coefficients when balancing chemical equations?

  Round up to the nearest whole number.
• What happens if you change the subscripts in the chemical formulas?

  You change the type of chemicals in the reaction.
• What does it mean if a chemical equation is balanced?

  There are equal numbers of each type of atom on both sides of the reaction, representing the conservation of mass.
• Balance the equation $H_2 +$$O_2 \rightarrow H_2O.$


  $2H_2 +$$O_2 \rightarrow 2H_2O$
• Balance the equation $CH_4 +$$O_2 \rightarrow CO_2 +$$H_2O.$


  $CH_4 +$$2O_2 \rightarrow CO_2 +$$2H_2O$
• Why is balancing chemical equations important for understanding reactions?

  Because it ensures that the number of atoms of each element is conserved during the reaction.
• What are the steps involved in balancing a chemical equation?

  1. Write the unbalanced chemical equation.
  2. Count the number of atoms of each element on both sides.
  3. Adjust coefficients to balance the number of atoms of each element.
  4. Ensure coefficients remain whole numbers.
  5. Double check that the equation is balanced.
• What should you do when balancing a chemical equation to ensure the number of atoms is equal on both sides?

  Adjust the coefficients in front of the chemical formulas.
• What happens if you do not balance a chemical equation correctly?

  The reaction does not obey the law of conservation of mass.
• What is the role of the single arrow in a chemical equation?

  It indicates that the reactants react completely to form the products.
• What is an important skill in science that is covered when balancing equations?

  Balancing chemical equations.
• Why is balancing chemical equations a crucial skill?


  It is important for many aspects of science.
• What are the two sides of a chemical equation called?

  • Reactants: substances that react together
  • Products: substances produced in the reaction
• What are the reactants in the equation $CH_4 +$$O_2 \rightarrow CO_2 +$$H_2O?$


  Methane $(CH_4)$ and Oxygen $(O_2).$
• What are the products in the equation $CH_4 +$$O_2 \rightarrow CO_2 +$$H_2O?$


  Carbon dioxide $(CO_2)$ and Water $(H_2O).$
• Why does a chemical equation use an arrow instead of an equal sign?

  • To indicate a chemical reaction
  • Shows the transformation of reactants into products