Rates of reactions Flashcards
Name the 4 factors that increase the rate of a reaction
Presence of a catalyst
Temperature
surface area
Concentration/pressure
What do the factors increase?
Increases the amount of energy atoms have = more energy they can transfer to other atoms in a collisons
Increased frequency of collisions= Not all collisions are succesful so more collisions mean more succesful collisions
How does temperature increase rate of reaction?
Temperature increases the amount of energy atoms have
This means that they will move faster and have a higher frequency of sucessful collisions
They will collide with more energy and most likely to succeed activation energy increasing rate of reaction
How does concentration/pressure increase rate of reaction?
Means more particles per unit of volume so more collisions leading a higher frequency of succesful collisions
How does surface area increase surface area?
E.g using a powder instead of a solid block
Allows more surface area to volume ratio for the collisions with other reactants to take place
giving more collisions and more successful collisions increasing rate of reaction
Name 3 ways to measure the rate of a reaction
Loss in mass of the reactants
volume of gas produced
time for a solution to become opaque
How does a catalyst increase rate of reaction?
- They speed up the reaction without being used in the reaction itself
- They lower the activation energy by providing alternative reaction pathways
This creates a higher porportion of succesful collisions
Name catalysts
Transition metals - colbalt + nickel
Biological catalysts - Enzymes
describe measuring the rate of a reaction by the opaqueness of it
Have a piece of paper with an X marked on it
Put the reactant flask on this cross
Mix the reagents and measure how long it takes for it too become opaque enough to conceal the cross
what is the collision theory?
chemical reactions can only occur when reacting particles collide with each with sufficient energy (activation energy)
what is a reversible reaction?
