Chapter 6.2

Question 1

What does the Le Chatelier’s principle state

Answer 1

• that if a stress is applied to a system
• > the system shifts to relieve that applied stress

-here Keq does not change but the reaction quotient changes

Question 2

How does Le Chatelier’s principle work with gases that have increasing pressure. Note the opposite of this is true for gases that have decreasing pressure.

Answer 2

• the system will move towards whichever side has the lower total number of moles of gas
• this is because as one increases the pressure of incompressible gas system
• > the volume decreases
• > so the system will prefer the side of the reaction that has gases with a lower total number of moles of gas

-here Keq does not change but the reaction quotient changes

Question 3

How does Le Chatelier’s principle work with temperature?

Answer 3

• change in temperature does not change the reaction quotient
• > it changes Keq

-the system has to move in whichever direction allows it to reach its new equilibrium state at the new temperature

For endothermic reactions

• > if heat is added, shift reaction to the right
• > if heat is removed, shift reaction to the left

For exothermic reactions

• > if heat is added, shift reaction to the left
• > if heat is removed, shift reaction to the right