Rate and Extent of Chemical Change Flashcards
(14 cards)
What are the four factors that affect the rate of a reaction?
Temperature, concentration/pressure, surface area, and presence of a catalyst.
Define ‘activation energy’.
The minimum energy required for particles to react when they collide.
How does increasing temperature increase reaction rate?
Particles gain kinetic energy, leading to more frequent and successful collisions (exceeding activation energy).
How does increasing concentration/pressure increase reaction rate?
More particles per unit volume, leading to more frequent collisions.
What is collision theory?
Reactions occur when particles collide with sufficient energy (activation energy) and correct orientation.
What is a catalyst?
A substance that speeds up a reaction without being used up, by lowering activation energy.
Describe the graph for a reaction with a catalyst.
The line will rise faster (steeper gradient) and reach the same final product amount as without a catalyst.
What is a reversible reaction?
A reaction where products can revert to reactants (e.g., heating hydrated copper sulfate).
What is dynamic equilibrium?
In a closed system, forward and reverse reactions occur at equal rates, so concentrations remain constant.
How does increasing temperature affect equilibrium (exothermic reaction)?
Shifts equilibrium to favor the endothermic (reverse) reaction to absorb excess heat.
How does increasing pressure affect equilibrium (if gaseous reactants/products have fewer moles)?
Shifts equilibrium to favor the side with fewer moles of gas to reduce pressure.
What is Le Chatelier’s principle?
If a system at equilibrium is disturbed, it adjusts to counteract the change.
How would you measure rate using gas collection?
Measure gas volume produced at regular time intervals and plot a graph of volume vs. time.
What does a steeper gradient on a reaction rate graph indicate?
A faster rate of reaction at that time.
