Chemistry » Rates of Chemical Change

Rates of Chemical Change

Key Words

Rate of reaction - how fast the reactants are changed into products. This depends on:

  • Temperature
  • Concentration of solution or pressure of gas.
  • Suface area
  • Catalyst

Collision frequency - how often they colide.

Activation energy - minimum amount of energy that particles need to react.

Reversible reactions - reactions that can go backwards.

Equilibrium - forward reactions go at the same rate as backward reactions

Dynamic equilibrium - forward and backward reactions are taking place but with no overall effect.

Closed system - none of the reactants or products can escape and nothing else can get in.

Position of equilibrium - if it lies to the right the concentration of products is greater than the reactants. If it lies to the left the concentration of reactants is greater than the products. Positioning depends on:

  • Temperature
  • Pressure
  • Concentration

Endothermic - energy is transferred from the surroundings.

Exothermic - energy is transferred to the surroundings.

Le Chatelier's Principle - if you change the conditions of a reversible reaction at equilibrium, the system will try to counteract that change.

 


PRACTICAL
Rates of Reaction

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Note paper for practical