Chapter 2: Equilibrium Flashcards
(15 cards)
What is an open system?
It allows matter and energy to be exchanged with its surrounding
What is a closed system?
It allows energy, but not matter to be exchanged with its surrounding
What is an endothermic reaction?
Requires energy, such as heat and has a +ve enthalpy
What is an exothermic reaction?
Releases energy, such as heat and have a -ve enthalpy
What is dynamic equilibrium?
The rates of forward and reverse reactions are equal
Explain how observable changes can be described at an atomic level
In a closed system, when the water particles energy becomes greater than the hydrogen bonding attracting the molecules, they break free into the gaseous state. When the temperature cools, they condense returning to the liquid. If an open system, when the water breaks free into a gaseous state, it escapes and so the water level will slowly decline.
What is Le Chatelier’s principle?
An equilibrium state can be manipulated by temperature, concentration and pressure
How does temperature affect equilibrium?
Exo reaction
Increase in temp = shift to left = reactants formed
Decrease in temp = shift to right = products formed
How does concentration affect equilibrium?
Increase in products = reactants formed
Decrease in products = products formed
How does pressure affect equilibrium?
Increase in pressure = less molecules favoured
Decrease in pressure = more molecules favoured
How does catalyse affect equilibrium?
It doesn’t
What is the equilibrium constant?
The mathematical relationship between the concentration of products and reactants
What is the equilibrium constant equation?
([C]^c x [D]^d)/([A]^a x [B]^b)
What is favoured if the kc value is greater than 1?
products
What is favoured if the kc value is greater less than 1?
reactants
