Rates of reaction Flashcards
What is the definition of rate of reaction?
The speed at which reactants are converted into products in a chemical reaction
Rate of reaction can be expressed in various units such as moles per liter per second.
What factors can affect the rate of a chemical reaction?
- Temperature
- Concentration/Pressure
- Surface Area
- Catalyst
These factors influence how often reactants collide and the energy of those collisions.
How does temperature affect the rate of reaction?
Higher temperatures increase the rate of reaction
Increased temperature raises the kinetic energy of molecules, leading to more frequent and effective collisions.
How does changing temperature alter the rate of reaction according to collision theory?
It increases the frequency and energy of collisions
Higher temperatures result in more molecules having the energy equal to or greater than the activation energy.
How can you calculate the rate of reaction at specific times using a graph?
By determining the slope of the tangent line at that specific time
The slope represents the rate of change of concentration over time.
How can the surface area of a solid be increased?
By breaking it into smaller pieces or grinding it into a powder
Increasing surface area allows more collisions between reactant particles.
How does changing the surface area change the rate of reaction?
Increasing the surface area increases the rate of reaction
A larger surface area allows more particles to collide with reactants.
How does collision theory explain the effect of surface area on the rate of reaction?
More surface area leads to more collisions
Increased collisions result in a higher probability of successful reactions.
How do you calculate surface area to volume ratio?
By dividing the surface area by the volume
This ratio affects the rate of reaction, especially in solid reactants.
How does changing concentration affect the rate of reaction?
Increasing concentration increases the rate of reaction
More reactant particles lead to a higher frequency of collisions.
How does changing concentration alter the rate of reaction according to collision theory?
It increases the number of effective collisions
Higher concentration means more reactant particles are available to collide.
How does changing pressure of gaseous reactants affect the rate of reaction?
Increasing pressure increases the rate of reaction
Higher pressure forces gas molecules closer together, leading to more collisions.
How does changing the pressure of gaseous reactants alter the rate of reaction according to collision theory?
It increases the frequency of collisions between reactant molecules
More collisions result in a greater chance of reaction occurring.
What is the activation energy of a reaction?
The minimum energy required for a reaction to occur
This energy is needed to break bonds in reactants.
What is a catalyst?
A substance that increases the rate of a reaction without being consumed
Catalysts lower the activation energy required for the reaction.
How does a catalyst affect the rate of a reaction?
It increases the rate of reaction by lowering the activation energy
This allows more molecules to participate in the reaction at a given temperature.
What can be identified from rates graphs regarding variables?
Dependent, independent, and control variables
Understanding these variables helps explain their effects on the rate of reaction.
True or False: A higher surface area results in a slower rate of reaction.
False
A higher surface area leads to a faster rate of reaction.
What is the method to use a tangent to calculate rate of reaction at a specific time?
Draw a tangent line at the point of interest and calculate its slope
The slope gives the rate of reaction at that specific moment.
