Equilibrium Case

Introduction

The scientific concept of this lab is proving Le Chatalier's principle. The principle states that when a system is at equilibrium is disturbed, the system will react to try to minimize the effect of that disturbance. When an addition of a reagent or a removal of a reagent will show a shift in equilibrium. Applying disturbance such as changing temperature, changing pressure and adding concentrations are factors that can disturb the equilibrium of a system. In this experiment, the concentrations will be focused on to prove the principle.

In chemical systems they will have a change in (delta)H, where deltaH would be positive, endothermic or negative, exothermic. When increasing the temperature in a system, it favours the endothermic reaction which shows a counteracting the change in temperature made by absorbing the excess heat and vice versa for decreasing temperature. When applying pressure, it is like forcing molecules to be closer together and when the molecules are going closer together the stress of the pressure can be relieved as the system has smaller molecules. Also when adding or removing a reagent causes a disturbance and according to the Le Chataliers principle, when adding a concentration the reactants will push towards the forward reaction and when removing some reactant it will push towards a backwards reaction.

The purpose of this experiment is to prove Le Chatalier's principle using solubility Equilibria, Complex Ion Equilibria and Acid/Base Equilibria. In solubility equilibria, a saturated solution of sodium chloride and by adding additional ions it will show what the system will do to relief stress on the addition ions added. Complex Ion Equilibria will be another way of showing le Chatalier's principle through an easy monitoring process because of the brightly coloured species. [Fe(NCS)] will be use because of its bright red complex ion and the addition of