10.1 Reaction Rates + Collision Theory

Question 1

Activation Energy

Answer 1

• The minimum energy that a particle needs in order to react
• OR the enthalpy difference between the reactants and the transition state
• A very small proportion of collisions result in a reaction as a molecule must have a certain min. energy enough to break bonds

Question 2

What is Collision Theory?

Answer 2

States that for a reaction to occur, particles:
=> (1) must collide
=> (2) must have sufficient energy - ACTIVATION ENERGY
=> (3) must collide with correct orientation - STERIC EFFECT

• most collisions aren’t successful due to (2) + (3)

Question 3

How to increase rate of reaction according to Collision Theory

Answer 3

=> More frequent collisions - increase particle speed (temp.) + more particles present in a certain volume (conc.)

=> More successful collisions - give particles more energy + lower activation energy (catalyst)

Question 4

What is “rate of reaction”?

Answer 4

• The rate of a chemical reaction tells the change in conc. of reactants or products in a given time
  (how quickly reactants ==> products)
• Equation: change in conc of reactant or product / time
• Units: moldm-3/s or moldm-3s-1