Rates of reaction

• What does the rate of chemical reactions refer to?

  The speed of reactants turning into products
• Why is it important to measure the rate of a reaction?

  To understand how fast reactants are used or products formed
• How can we measure the rate of a 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
• What units can be used to measure quantities in the rate of reaction?

  Grams or cm cubed
• 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 with many reactants
  • Slows down as reactants are used up
• What does a graph of mass of reactant remaining show over time?

  Mass starts high and decreases over time
• What does a graph of volume of product produced show over time?

  Volume starts at zero and increases quickly
• What other units can be used for measuring rates of reaction?

  Moles or decimet cubed per second
• Rate of reaction examples:

  Slow:iron rusting

  Moderate: magnesium reacting with an acid to produce a gentle stream of hydrogen bubble

  Fast:explosions like fireworks
• why does the reaction start at 0 in a product formed graph?

  no products are formed yet