OZ 4 Rate Of Reaction Flashcards
What is the rate of reaction?
The rate at which reactants are converted into products.
How do you calculate the rate of reaction?
Change in property / time taken.
What does a colorimeter do?
Measures the change in colour of a reaction.
What is chemical analysis?
Samples of the reaction are taken at regular intervals, and then the reaction is quenched (stopped) before analysis.
What is quenching?
Stopping a reaction.
What affects the rate of reaction?
The concentration of reactants in a solution, the pressure of reacting gases, the temperature, the intensity of radiation, the particle size and surface area of a solid, and the presents of a catalyst.
What is concentration in solutions proportional to in gases?
The pressure.
Why does powder react faster than a lump of solid?
There is a much larger surface area of solid exposed for the reaction to take place.
What is the transition state?
The highest point on the pathway of an enthalpy profile.
What state occurs for a very short time?
The transition state.
Why do reactions go faster at higher temperatures?
A larger proportion of the colliding molecules have the minimum activation enthalpy needed to react.
What measures the rate of reaction?
The volume of gas evolved, change in mass, change in colour by colorimetry, pH measurement, and chemical analysis.
