Physical Chemistry Flashcards
What is a reversible reaction?
A chemical reaction that can take place forwards or backwards. This starts a cycle that does not end, just reaches equilibrium.
What is equilibrium?
The point where there is no further change in the concentration of any species in the reversible reaction.
What is Collision Theory?
Molecules + atoms + ions can react to form products when they collide if the particles have sufficient kinetic energy.
What is activation energy?
The minimum energy that colliding particles must have in order to react.
What is the effect of temperature on the rate of reaction?
Temp. (up) = Speed of reaction (up) because particles have increased KE so move faster so the frequency of successful collisions (up).
What is the effect of concentration on the rate of reaction?
Concentration (up) = Higher no. particles in a fixed volume so frequency of collisions (up) so reaction rate (up).
What is the effect of particle size on the rate of reaction?
Particle size (drop) = Surface area (up) for said mass of particles so frequency of collisions (up) so reaction rate (up).
What is the effect of a catalyst on the rate of reaction?
Enables reaction to proceed along a lower energy path (lower Ea) without being used up so reaction rate (up).
What is Le Chatelier’s Principle?
If a dynamic equilibrium is disturbed by changing the conditions, the position of equilibrium shifts to counteract the change to establish an equilibrium.
What is the effect of temperature on equilibrium?
Temperature (up) = Favours endothermic reaction. Temperature (drop) = Favours exothermic reaction.
What is the effect of concentration on equilibrium?
Reactant concentration (up) = Forward reaction favoured. Product concentration (up) = Reverse reaction favoured.
What is the effect of pressure on equilibrium?
Pressure (up) = Favours side (reaction) with more gas molecules involved. Pressure (drop) = Favours side with fewer gas molecules involved.
What is the equilibrium constant and the equation?
The exact position of equilibrium. The magnitude shows whether there are more reactants or products in the system.
Kc = (Products) / (Reactants).
What is an ICE Table used for?
To show shifts in the position of equilibrium (Initial, Change, Equilibrium).
