Calculating Reaction Rates Flashcards
What is meant by the term reaction rate?
This is the rate at which a product is formed or a reactant is used up.
How do you find the rate of reaction?
amount of reactant used up or product formed/time
What are the two ways in which you can investigate reaction rates?
By measuring how quickly the products are formed or how quickly the reactants are used up.
How can you measure how quickly a product forms?
Change in mass or volume of gas given off.
How do you measure the change in mass?
Measure the mass at given intervals until the mass stays the same.
What do the products have to be when investigating the rate of reaction using mass?
The products have to be a gas.
What piece of apparatus is used to measure the volume of gas given off?
A gas syringe.
What does a gas syringe measure?
The volume of product formed.
How do you measure the volume of gas given off?
Take recordings from the gas syringe at regular intervals until there is no change.
What is a problem with using a gas syringe?
Vigorous reactions can blow the plunger off the syringe.
How else could you measure the rate of reaction?
Changes in pressure, colour or conductivity.
To work out the rate of reaction from a graph, what does the x axis have to be?
Time
To work out the rate of reaction from a graph, what does the y axis have to be?
Either a measure of the amount of product or the amount of reactant.
How do you find the reaction rate from a graph?
Find the gradient.
How do you find the gradient of a line graph?
change in y/change in x
