Study

AQA Chemistry Rates of Reaction

  •   0%
  •  0     0     0

      Back   Restart
  • What is activation energy?
    The amount of energy needed to start a reaction
  • If we increase the concentration of a reaction in equilibrium, will the reaction shift in the forward or backward direction?
    Forward
  • Give an example of the units for a rate of reaction?
    g/s or cm3/s
  • If a reaction is equilibrium is exothermic in the forward direction, what does that mean for the backward reaction?
    It will be endothermic
  • Explain how increasing the concentration of a reactant will change the rate of the reaction
    There are more particles per unit volume, so more frequent collisions and a faster rate of reaction
  • What does it show when the line of the graphs has levelled off (gone flat)?
    That the reaction has stopped
  • What two things must happen for particles to react?
    They must collide and with enough energy for the collision to be successful
  • What does it mean if a reaction is in equilibrium?
    The rate of the forward and backward reactions are the same
  • What does this show?
    Reversible reaction
  • Explain how a catalyst changes the rate of a reaction
    It speeds up the reaction by lowering the activation energy, meaning there are more successful collisions
  • What are the two ways to calculate the rate of a reaction?
    quantity of reactant used divided by time or quantity of product formed divided by time 
  • What is the name of the piece of equipment labelled B?
    Conical flask
  • How can we increase the surface area of a solid?
    Grind it up into a powder/cut it into smaller pieces
  • For both reactions, A and B, the rate of reaction slows down as time progresses. Why does this happen?
    The reactants are being used up in the collisions, so their concentration decreases. This means less frequent collisions until one reactant is used up
  • Explain how decreasing the temperature of a reaction changes the rate of a reaction
    The particles will have less energy, so there are less successful collisions and a slower rate of reaction
  • What is the name of the piece of equipment labelled A?
    Gas syringe
  • If we decrease the pressure of a reaction in equilibrium, which direction will the reaction shift in? Hint: think about the number of molecules
    Towards the side with more molecules
  • What are the 5 factors that effect the rate of a reaction?
    Concentration, temperature, pressure, surface area and catalysts
  • Use the green tangent line to calculate the rate of this reaction
    60/5 = 12 cm3/s
  • What are the two methods for measuring the volume of gas produced in a reaction?
    Gas syringe or measuring cylinder filled with water
  • When we increase the temperature of a reaction in equilibrium, what direction will the reaction shift towards?
    The endothermic direction
  • Which line, A or B, shows the fastest reaction? Explain your choice.
    A because the line starts steeper or there is more gas produced in a shorter time
  • What is the name given to the energy that particles must have for a collision to be successful?
    Activation energy
  • Which reaction, A or B, finishes first? How can you tell?
    A because the line levels off in the shortest amount of time
    • Your experience on this site will be improved by allowing cookies.