Rate of reaction

• What does the rate of chemical reactions refer to?

  The speed of reactants turning into products
• How can we measure the rate of a chemical reaction?

  By measuring reactants used or products formed
• What is the equation for the rate of reaction based on reactants used?

  Rate = quantity of reactants used / time
• What is the equation for the rate of reaction based on products formed?

  Rate = quantity of products formed / time
• If 180 cm cubed of hydrogen is produced in 2 minutes, what is the rate?


  1.5 cm cubed per second
• How do you convert 2 minutes into seconds?

  120 seconds
• If 3 g of magnesium takes 4 minutes to disappear, what is the rate?

  0.0125 g per second
• What do the calculated rates of reaction represent?

  The average or mean rates throughout the reaction
• How does the rate of reaction change over time?

  Starts fast, then slows down as reactants are used
• How can we visualize the rate of a reaction over time?

  • Plot graphs with time on x-axis
  • Mass of reactant or volume of product on y-axis
• What happens to the mass of magnesium in a reaction graph?

  It starts high and decreases over time
• What happens to the volume of hydrogen produced in a reaction graph?

  It starts at zero and increases rapidly
• How do you calculate the rate in moles per minute if 0.6 moles of magnesium are used in 2 minutes?

  0.3 moles per minute
• What units can be used to express the rate of reaction?

  • Grams per second
  • cm cubed per second
  • Moles per second
  • Decimet cubed per second
  • Moles per minute
• What will the next video cover regarding the rate of reaction?

  Calculating the rate at a specific time
• What should viewers do if they enjoyed the video?

  Like and subscribe
• What is the difference between average and instantaneous rates of reaction?

  Average is over the entire reaction; instantaneous is at a specific time
• What factors can affect the rate of chemical reactions?

  • Concentration of reactants
  • Temperature
  • Presence of catalysts
  • Surface area of reactants
  • Pressure (for gases)
• How does temperature affect the rate of chemical reactions?

  Higher temperatures generally increase reaction rates
• What is the role of catalysts in chemical reactions?

  Catalysts speed up reactions without being consumed
• What is activation energy in chemical reactions?

  The minimum energy required for a reaction to occur
• How does surface area affect reaction rates?

  Larger surface area increases reaction rates
• How does pressure influence gaseous reactions?

  Higher pressure increases reaction rates for gases