Chapter 6 - Equilibria Flashcards
What does Le Chateliers principle state?
Any reaction a closed system has done to it, it will act to reverse the change
What is happening to a closed system and its compounds at equilibrium?
The two reactions are happening in opposite directions at the same rate, meaning the concentration of the reactants and the products remains constant
How does a catalyst affect a closed system?
All a catalyst does is speed up both the forward and backwards reaction of a system, it does not influence the position of equilibrium
3H2 + 2N2 -> <- 2NH3 - what is this reaction and why are its conditions a compromise?
This is the Haber process, and it has a compromise in temperature because it is an exothermic reaction, so higher temperatures favour the left hand side which reduces yield, however it does speed the reaction up. The pressure is a compromise because increased pressure would both increase the yield and rate of reaction, therefore it is favourable to have it as high as possible, however this has serious safety concerns as well as cost to maintain the increased pressure
What is Kc?
It is the equilibrium constant, which predicts how a system will react to differing concentrations kept at the same temperature
Give an expression for the Kc of the reaction 2A + B -> <- C + 2D. What would be the units?
Kc = [C] X [D]^2 / [A]^2 X [B]. In this equation Kc would have no units because there are equal amounts of moles of concentration on both the top and bottom, therefore they cancel out
Which two things do not affect Kc, and which thing does affect Kc?
Kc is not affected by changes in concentration or catalyst, however it is affected by temperature
