Rates of reactions

• Who is presenting the video on measuring chemical reaction rates?

  1. Mitchell
• What are the two methods used to measure the rate of a chemical reaction?

  Measuring cylinder and gas syringe
• Which two substances are used in the reaction?

  Magnesium and hydrochloric acid
• What concentrations of hydrochloric acid are being compared?

  2 mol/dm³ and 1 mol/dm³
• What does 2 mol/dm³ mean in terms of hydrochloric acid?

  Two moles per liter of solution
• How much hydrochloric acid is measured for the experiment?

  50 cm³
• Why is it important to read the measuring cylinder at eye level?

  To accurately see the bottom of the meniscus
• What is the purpose of the bung in the conical flask?

  To prevent gas from escaping
• How is gas production measured in the first method?

  By observing the displacement of water
• What should be done every 10 seconds during the experiment?

  Record the gas produced
• What is the alternative method to measure gas production?

  Using a gas syringe
• What must be kept dry when using a gas syringe?

  The gas syringe itself
• What is plotted on the graph of results?

  Time and volume of gas collected
• What does a steeper curve on the graph indicate?

  A faster rate of reaction
• Why do the results reach the same point in the experiment?

  Magnesium is the limiting reactant
• What are some sources of error in the experiment?

  Timing and gas loss at the start
• Why is the measuring cylinder considered imprecise?

  It only measures in 1 cm³ increments
• What would improve the precision of gas measurement?

  Using an inverted burette