rate and extent of chemical change

• What does collision theory state?

  Reactions occur when particles collide with sufficient energy
• What happens to equilibrium if pressure is increased?

  Equilibrium shifts to the side with fewer moles
• What happens to equilibrium if pressure is increased?

  Equilibrium shifts to the side with fewer moles
• What is another way to express the quantity of reactants?

  In terms of moles
• What happens if the concentration of a reactant is increased?

  Equilibrium shifts towards the products
• How can the direction of a reversible reaction be changed?

  By changing the conditions of the reaction
• How does increasing concentration affect reaction rates?

  It increases the frequency of collisions
• What is activation energy?

  The minimum energy required for particles to react
• What factors affect the rates of chemical reactions?

  • Concentration
  • Pressure
  • Surface area
  • Temperature
  • Catalysts
• How does an increase in temperature affect equilibrium?

  Equilibrium moves towards the endothermic reaction
• How does pressure affect yield in reactions producing different volumes of gas?

  • Larger volume of gas (more moles):
  • Increase in pressure: Decreases yield
  • Decrease in pressure: Increases yield
  • Smaller volume of gas (fewer moles):
  • Increase in pressure: Increases yield
  • Decrease in pressure: Decreases yield
• How can the rate of reaction be found graphically?

  By drawing tangents to curves and using the slope
• How can rates of reactions be measured?

  By amount of product used or formed over time
• What is the formula for the rate of reaction using reactants?

  Rate of reaction = amount of reactant used / time
• What is the formula for the rate of reaction using products?

  Rate of reaction = amount of product formed / time
• How can the quantity of reactant or product be measured?

  By mass in grams or volume in cm³
• What are the units of rate of reaction?

  g/s or cm³/s
• How can quantity of reactants be expressed in terms of moles?

  Using moles instead of mass or volume
• What are the units for rate of reaction in moles?

  mol/s
• How can the rate of reaction be found graphically?

  By drawing tangents to curves and using slopes
• What does the gradient of a tangent represent in reaction rate graphs?

  It measures the rate of reaction at a specific time
• What factors affect the rates of chemical reactions?

  • Concentration
  • Pressure
  • Surface area
  • Temperature
  • Catalysts
• What is collision theory in chemical reactions?

  Reactions occur when particles collide with sufficient energy
• What is activation energy?

  The minimum energy required for particles to react
• How does increasing concentration affect reaction rates?

  It increases the frequency of collisions
• How does increasing temperature affect reaction rates?

  It increases collision frequency and energy
• What are catalysts in chemical reactions?

  Substances that speed up reactions without being used
• What role do enzymes play in biological systems?

  They act as catalysts
• What are reversible reactions?

  Reactions where products can form reactants
• Are catalysts included in the reaction equation?

  No, they are not included
• How do catalysts affect activation energy?

  They decrease activation energy required for reactions

  
• How can the direction of a reversible reaction be changed?

  By changing the conditions of the reaction
• What symbol is used to represent a reversible reaction?

  ⇌
• What do catalysts provide for chemical reactions?

  A different pathway with lower activation energy

  
• What is an example of a reversible reaction?

  The Haber Process
• What happens if a reversible reaction is endothermic one way?

  It is exothermic in the opposite direction
• How much energy is transferred in a reversible reaction?

  The same amount is transferred each way
• What is equilibrium in a reversible reaction?

  When reactions occur at the same rate in both directions
• What affects the relative amounts of substances at equilibrium?

  The conditions of the reaction
• What does Le Chatelier's principle state?

  The system responds to counteract changes