Rate and Extent Of Chemical Change (C6 Topic) Flashcards
In a rate of reaction graph, what do steeper lines at the start show?
Faster rate of reaction
In a rate of reaction graph, what do the flat lines at the end show
That the reaction has finished
How can more product be formed when the reaction is finished?
By using more reactant
What is the equation to find the mean rate of reaction?
Mean rate of reaction= Amount of product formed (or reactant used)
-Divided by Time.(s)
How to find rate at a specific point on rate graphs?
Drawing a tangent to the curved line using change in y and change in x
What can affect the Rate of reaction?
Temperature
Pressure/ Concentration
Surface Area
Catalyst
What is collision theory?
The more collisions between particles, the faster the rate of reaction.
What is collision energy?
Enough energy needs to be transferred in a collision to overcome the activation energy and break the bonds to start a reaction.
What is activation energy?
Minimum energy particles need to react.
Why is temperature a “catalyst?”
Particles move faster and collide more frequently with more energy- heat is energy
Why is Pressure/ Concerntration a “catalyst?”
More particles in the same volume =more frequency collisions
Why is Surface area a “catalyst?”
More area for particles to collide with = more frequent collisions
(Imagine a cube cut into 4- the inner faces of the cube act as extra surface area)
What is a catalyst?
Speeds up a reaction without being used up itself.
The smaller a piece of solid, the larger the ___ to ____ ratio?
Surface Area to volume ratio.
When can equilibrium be reached?
Only when a reversible reaction takes place in a closed system?
What is a closed system for a reaction?
Where nothing can enter or leave.
What is a reversible reaction?
Where products can react to form the reactants again.
With reversible reactions, if it is endothermic in one direction, what must it be in the other?
Endothermic in the other direction.
What is Le Chateliers Principle?
If the conditions of a reversible reaction at equilibrium are changed, the system tries to counteract that change.
If temperature increases the equilibrium will shift to favour what direction and why?
Endothermic direction to take in heat energy.
If temperature decreases the equilibrium will shift to favour what direction and why?
Ectothermic direction to release heat energy
If pressure increases the equilibrium will shift to favour what side and why?
The side with fewer molecules of gas to reduce pressure
If pressure decreases the equilibrium will shift to favour what side and why?
The side with more molecules of gas to increase the pressure
If the concentration of reactants increase, the system responds to…?
Make more products
If the concentration of reactants decrease, the system responds to…?
Make more reactants
