C6 Rate of Reaction Flashcards
Give two ways you can measure the rate of a reaction.
Measure the rate the reactant gets used up or the rate the product is formed (e.g. collect a gas made)
What units are used for rate of reaction if a gas is collected?
cm3/s
In terms of the reactants - when do reactions end?
When the reactants are all used up
What is the collision theory ? ?Reactions only occur when..?
?Reactions only occur when..particles collide with enough energy?
In terms of collisions, why are some reactions faster than others?
More frequent collisions
Why does increasing concentration increase the rate of reaction?
More frequent collisions
Why does increasing pressure of gases increase the rate of reaction?
More frequent collisions
Why does breaking reactants up into smaller pieces increase the rate of reaction?
More frequent collisions
Why does increasing the temperature increase the rate of reaction (two reasons)?
More frequent collisions AND more of the collisions are successful (collide with more energy)
What is a catalyst?
A substances that changes the rate of a reaction but is not used up.
Why does adding a catalyst increase the rate of the reaction?
It lowers the activation energy
What is the name given to biological catalysts?
Enzymes
What is the symbol for a reversible reaction?
(see diagram)
If a reaction is exothermic in the forward direction what can you say about the same reaction in the other direction?
endothermic
What can you about the rate of the forward and backward reactions at equilibrium?
They are the same
