rate of reaction Flashcards
what is rate of reaction?
how fast the reactants are changed into products
rate of reaction formula
amount of reactant used or amount of products formed / time
3 different ways to measure rate of reaction
1) precipitation and colour change
2)change in mass (usually gas given off)
3)the volume of gas given off
example of a slow reaction
chemical weathering like acid rain damage to limestone building
Example of a fast reaction
burning
explosions
the steeper the line on the graph
the faster the rate of reaction
the quickest reactions have the…. (graph)
steepest lines and become flat in the least time
4 factors affecting rates of reaction
temperature
the concentration of a solution or the pressure of gas
surface area
the presence of a catalyst
the minimum amount of energy that particles need to react is called
activation energy
what is activation energy?
the minimum amount of energy that particles need to react is called
The rate of a chemical reaction can be found by measuring the…
quantity of a reactant used or the quantity of product formed over
time
equation to find the mean rate of reaction
quantity of reactant used/time taken
quantity of product formed/ time taken
steps for calculating the rate of reaction on a graph
(higher only)
graw the tangent
read the values of x and y axis
rate of reaction=gradient of tangent
effect of concentration on rate of reaction
increases the rate of reaction-number of successful collisions per second
describe a graph using collision theory
reaction is rapid at the start as we have many reactant molecules meaning we have many reactions per second. over time the reactions start to slow down because the number of reactant molecules is running out meaning we have a smaller number of collisions per second.
