C6 Flashcards
What is rate of reaction
How fast reactants are changed into products
What do reaction graphs represent
The amount of product formed or reactants used up over time
What is collision theory
When particles collide with enough activation energy to react. The more frequent the collisions are, the faster the reaction is. Energy is transfered between particles so particles must have enough ectivation energy in order for reaction to occur
What are the 4 things that affect rate of reaction
. Tempurature
. Concentration
. Surface area
. Catalyst
How does temp affect the rate of reaction
Increase temp means particles move faster as have more kinetic energy. Leads to more successful collisions occuring so rate increase
How does increasing concentration and pressure increase reaction rate
More concentration means more particles so more particles to collide with so successful collisions occur more frequently
Increase pressure means more particles in a smaller space. This means there is more frequent collisions with walls and other particles
How does increasing surface area increase reaction rate
More surface area means more surface to collide with so collisions occur more frequently
How does using a catalyst increase reaction rate
. Speed up reaction rate without being used up. They decrease amount of activation energy needed for reaction to occur. They do this by providing alternate pathway with lower activation energy
What is the equation for finding out the rate of a reaction
Amount of reactant used or product formed divided by time
What are the 3 ways to measure the rate of reaction
. Precipitation and colour change
. Change in mass if gass given off
. Measure volume of gass given off - done using gass siringe. The more gass given off, the faster the reaction
Magnisium and hydrochloric acid practical
Sodium thiosulfate and hydrochloric acid practical
How do u calculate the mean reaction rate from a graph
Overall change in y value ÷ time take
How do u find the rate of a reaction at a particular point on a graph
Draw Tangent and find gradient
What is a reversable reaction
A reaction where the products created can turn back into the reactants
What is equalibrium
Tells us how many reactants there are compared to how many products there are. When equalibrium lie to the right, it means concentration of products greater than can concentration of reactants. Of lie to the left it’s the opposite
What else can reversable reactions be
Exothermic - to the right
endothermic - to the left
What is chanteliers principle
It is the idea that if you change the conditons of a reversable reaction at equalibrium, the system will try to counteract that change
How can chanteliers principle be used to predict the affect of change in temp you make to a reaction system
Decrease temp - equalibrium shift to exothermic side to produce more heat
Increase - shift to endothermic side to decrease it
How can chanteliers principle be used to predict the affect of change in pressure you make to a reaction system
. Only affects equalibrium involving gasses
. Increase - equalibrium shift to side with fewer gass molecules
. Decrease - move to side with more gass molecules
How can chanteliers principle be used to predict the affect of change in concentration you make to a reaction system
Increase concentration reactants - produces more products
. Decrease consentration of products - reduce concentration of reactants
