April 23 : Equilibria

In class today, we covered the "Introduction to Equilibria" which investigated how changing conditions affects the position of equilibrium.

We conducted two experiments that demonstrated the Le Chatelier's principles taking affect onto systems of equilibrium: The Iron Thiocyanate Complex & The 'Fried Eggs' of PbI2 and KPbl3.

Both experiments showed how adding different solutions/conditions shifted the equilibrium to either the reactant side (causing a change in color) or the product side (also, causing a change in color).

Homework:
Finish the Equilibria practice questions (#1-6) we were given/ we started in class

Equilibrium 21/04/15

Equilibrium 21/04/15

EQUILIBRIUM

Material:

Covered in class included:

Concept of chemical equilibrium - is when a system has no net change in concentration of reactant and products, where forward and backward reactions are both taking place at the same time at the same rate. 

Le Chatelier - a chemist who came up with the principle that a system at equilibrium will shift so as to oppose any change made to it (counter the changes made to it).

Work in class:

To demonstrate the concept of equilibrium we were given specific amount of M&M's and were made to use them in different simulations. In each there would be one holder of M&M's who represented the reactants, and one holder of M&M's who represented the products. The reactant each time would transfer 1/2 of their quantity to the products, and the products would give 1/4 of their quantity to the reactants. Eventually the system would reach an equilibrium where both were giving each other the same amount. This was then repeated with varying amounts of M&M's and fractions given to each holder.

Mr. Carmichael then went on to demonstrate another explanation of equilibrium where colour was involved. In this demonstration we wrote on a worksheet that described each situation well, and we would explain the changes we would see. Refer to this sheet for further detail. From the experiment we learnt that if a catalyst was added to a reaction it would not effect the equilibrium position, but instead just get to the equilibrium faster.Also that if there is a higher pressure exposed to a reaction it will shift it's equilibrium to the side with less moles of gas to even it's self out.

Graphs covering equilibrium:

Homework:

The homework assigned today was to read pages 218-220 in the SL textbook, to take notes on physical equilibrium, and to highlight the sheet given at the end of class.