Rate of reaction

• what is the rate of reaction

  A measure of how fast a reactant is used up or how fast a product is made
• Three techniques used in a lab that are used to measure ror

  measuring mass loss

  measuring volume of gas produced

  colour change
• equation

  rate = amount of reactant used / time taken
• What is the relationship between collision frequency and reaction rate?

  The greater the frequency, the greater the rate
• What is a reactant in a chemical reaction?

  A substance that reacts to form products
• How is the rate of a reaction defined?

  Measure of how quickly reactants are used or products formed
• What must happen for a chemical reaction to occur according to collision theory?

  Reactant particles must collide with enough energy
• What is a successful collision?

  A collision that produces a reaction
• What is activation energy?

  The minimum energy needed for a reaction
• How does activation energy vary?

  It is different for different reactions
• When is measuring mass useful in a reaction?

  When carbon dioxide is a product leaving
• What units are typically used for measuring rate when mass is involved?

  g/s or g/min
• How can the volume of a gas be measured during a reaction?

  Using a gas syringe or an upside-down burette
• What units are typically used for measuring rate when volume is involved?

  cm³/s or cm³/min
• How can the rate of reaction be analyzed graphically?

  • Plot mass or volume of product against time
  • Steeper line indicates a greater rate of reaction
  • Horizontal line indicates the reaction has finished
• What does the gradient of a reaction rate graph represent?

  The rate of reaction
• What is another unit for measuring the rate of a chemical reaction?

  Mol s$^{-1}$
• How can fast reactions be identified on a graph?

  By the line becoming horizontal sooner
• What is the significance of collision theory in chemical reactions?

  It explains how reactions occur through particle collisions
• What is a product in a chemical reaction?

  A substance formed during a reaction
• Why is measuring changes in mass or volume important?

  It helps determine the rate of reaction
• How does the gradient of a reaction rate graph relate to the reaction rate?

  A steeper gradient indicates a faster reaction
• How does temperature affect reaction rates?

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

  Catalysts increase the rate of reactions
• How does concentration influence reaction rates?

  Higher concentration usually increases reaction rates
• What is the effect of surface area on reaction rates?

  Larger surface area generally increases reaction rates
• What would you see when sodium hydroxide solution is added drop by drop to tap water containing aluminium ions?


  produces a white precipitate then dissolves
• The student could show that the filtered water contains dissolved salts without using a chemical test. Describe how.


  put a sample of the filtered water in an evaporating basin there will be crystals of salt left