2.1 Rates of reaction

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Created by
ilhan

Cards (11)

  • How is rate of reaction calculated?
    Rate of reaction = quantity of reactants used (g or cm3) / time (s)
    Rate of reaction = quantity of product formed (g or cm3) / time
  • Units for rates of reaction?
    g/s or
    cm3/s or
    mol/s
  • Three common ways of measuring rate of reaction?
    • Loss in mass in reactants
    • Volume of gas produced
    • Time for a solution to become opaque
  • Four factors affecting the rate of chemical reaction
    • Concentration/ pressure
    • Surface area
    • Temperature
    • Catalyst
  • What is the collision theory?
    Chemical reaction can only occur when reacting particles collide with each other with sufficient energy ( activation energy)
  • Describe and explain the effect of increasing temperature on the rate of reaction
    Temperature increases = more faster as they have more energy
    As they move faster, they collide more frequently.
    Higher rate of reaction
  • Describe and explain the effect of increasing concentration/pressure on the rate of reaction
    Concentration/ pressure is how many particles in a solution/ gas per unit of volume.
    Concentration/ pressure increases = more particles
    More particles = more frequent collisions
    Increase rate of reaction
  • Describe and explain the effect of increasing surface area
    If solid particles are I. Smaller pieces they have a greater surface area.( powder >solid /small chunks)
    Increasing surface area, increases the frequency of collisions and so increase the rate of reaction.
  • What is a catalyst and how does it work? How does it affect the reaction profile?
    A catalyst changes the rate of reaction but is not used up.
    It increases rate of reaction by providing a different pathway for the reaction that has a lower activation energy. The reaction profile for a catalysed reaction will have a lower maximum of the curve (lower activation energy).
  • What is a reversible reaction?
    A reversible reaction occurs when the products of a reaction can react backwards to produce the original reactants
  • When is dynamic equilibrium reached?
    In a closed system, when the forward and reverse reactions occur at the same rate and the concentrations of reactants and products remain constant.