Lab Report on Le Chatelier's Principle
LE CHATELIER’S PRINCIPLE
Castro, Lharize C.
Experiment # 1
I. Introduction: In this experiment, using Le Chatelier’s principle, we will observe several responses of a system at equilibrium to various changes in external conditions. The experiment aims to investigate two equilibrium systems: (a) cobalt complexes and (b) chromate-dichromate equilibrium and explain observations in light of the Le Chatelier’s principle.
II. Theory/Concepts: In 1884 the French chemist and engineer Henry-Louis Le Chatelier proposed one of the central concepts of chemical equilibria. Le Chatelier's principle can be stated as follows: A change in one of the variables that describe a system at equilibrium produces a shift in the position of the equilibrium that counteracts the effect of this change.
Le Chatelier's principle describes what happens to a system when something momentarily takes it away from equilibrium. When a system at equilibrium is disturbed, the equilibrium position will shift in the direction which tends to minimize, or counteract, the effect of the disturbance. * If the concentration of a solute reactant is increased, the equilibrium position shifts to use up the added reactants by producing more products.
* If the pressure on an equilibrium system is increased, then the equilibrium position shifts to reduce the pressure. * If the volume of a gaseous equilibrium system is reduced (equivalent to an increase in pressure) then the equilibrium position shifts to increase the volume (equivalent to a decrease in pressure) * If the temperature of an endothermic equilibrium system is increased, the equilibrium position shifts to use up the heat by producing more products. * If the temperature of an exothermic equilibrium system is increased, the equilibrium position shifts to use up the heat by producing more reactants.
III. Materials: Reagents: Apparatus: * 0.4 M CoCl2 ő graduated cylinder * 0.5 M HCl ő
Castro, Lharize C.
Experiment # 1
I. Introduction: In this experiment, using Le Chatelier’s principle, we will observe several responses of a system at equilibrium to various changes in external conditions. The experiment aims to investigate two equilibrium systems: (a) cobalt complexes and (b) chromate-dichromate equilibrium and explain observations in light of the Le Chatelier’s principle.
II. Theory/Concepts: In 1884 the French chemist and engineer Henry-Louis Le Chatelier proposed one of the central concepts of chemical equilibria. Le Chatelier's principle can be stated as follows: A change in one of the variables that describe a system at equilibrium produces a shift in the position of the equilibrium that counteracts the effect of this change.
Le Chatelier's principle describes what happens to a system when something momentarily takes it away from equilibrium. When a system at equilibrium is disturbed, the equilibrium position will shift in the direction which tends to minimize, or counteract, the effect of the disturbance. * If the concentration of a solute reactant is increased, the equilibrium position shifts to use up the added reactants by producing more products.
* If the pressure on an equilibrium system is increased, then the equilibrium position shifts to reduce the pressure. * If the volume of a gaseous equilibrium system is reduced (equivalent to an increase in pressure) then the equilibrium position shifts to increase the volume (equivalent to a decrease in pressure) * If the temperature of an endothermic equilibrium system is increased, the equilibrium position shifts to use up the heat by producing more products. * If the temperature of an exothermic equilibrium system is increased, the equilibrium position shifts to use up the heat by producing more reactants.
III. Materials: Reagents: Apparatus: * 0.4 M CoCl2 ő graduated cylinder * 0.5 M HCl ő
References: http://www.ausetute.com.au/lechatsp.html http://chemed.chem.purdue.edu/genchem/topicreview/bp/ch16/lechat.html