Chemistry: Chemical Reactions Flashcards
Describe the effect of concentration, particle
size, catalysis and temperature on the rate of
reaction.
Concentration - Increase generally increases rate of reaction as there are more reactants to form products.
Particle Size - Reaction rate is linearly dependent on particle size. Smaller reactant particles provide a greater surface area which increases the chances for particle collisions so the reaction rate increases.
Catalysis - Catalyst provides alternate route for reaction. Alternate route has lower activation energy, thus increase.
Temperature - Positive correlation. More activation energy.
Describe a practical method for investigating
the rate of a reaction involving gas evolution.
Remove impurities from magnesium strip using sandpaper.
Pour excess hydrochloric acid into conical flask
Add magnesium strip into flask
Quickly put on stopper and gas syringe
Measure how much the syringe moves back every 30 seconds. This will show the speed of the reaction.
Interpret data obtained from experiments
concerned with rate of reaction.
Both experiments will produce the same amount of product as the amount of reactants put in are the same. However, the experiment that is faster will have reached the maximum amount quicker. Calculate the average rate of reaction for each experiment and compare.
Describe and explain the effects of
temperature and concentration in terms of
collisions between reacting particles (the
concept of activation energy will not be
examined).
Temperature has a positive correlation with reaction speed.
Concentration, too, has a positive correlation.
Define catalyst as an agent which increases
rate of reaction but which remains
unchanged.
Catalyst is an agent which increases rate of reaction, but itself remains unchanged.
Define oxidation and reduction in terms of
oxygen loss / gain, and identify such reactions
from given information.
Oxygen is :)
