18 flashcards · Shared on 19 August 2026 by AtomAI Library
Flip each card to check yourself.
What is the rate of a chemical reaction?
The change in amount or concentration of a reactant or product per unit time
What is the rate of a chemical reaction?
The change in amount or concentration of a reactant or product per unit time
In collision theory, what makes a collision successful?
The particles collide with enough energy and a suitable orientation
What is activation energy?
The minimum energy that colliding particles need for a reaction to occur
Why does increasing reactant concentration usually increase reaction rate?
It places more reactant particles in a given volume, increasing collision frequency
How does increasing the pressure of gaseous reactants usually affect reaction rate?
It increases the rate because gas particles are closer together and collide more often
Why does a powdered solid usually react faster than the same mass in one large piece?
The powder has a larger surface area exposed to the other reactant
What are the two main effects of increasing temperature on reacting particles?
They collide more frequently, and a greater fraction have energy at least equal to the activation energy
How does a catalyst increase the rate of a reaction?
It provides an alternative reaction pathway with a lower activation energy
What happens to a catalyst during a reaction?
It takes part in the mechanism but is regenerated overall
On a graph of product formed against time, what does a steeper gradient show?
A faster reaction rate
Why does the rate of many reactions decrease as the reaction proceeds?
Reactants are used up, so their concentrations fall and successful collisions become less frequent
A reaction produces 60 cm³ of gas in 30 seconds. What is its average rate of gas production?
2 cm³/s
Which method is most suitable for following the rate of a reaction that produces a gas?
Measuring the volume of gas collected at regular time intervals
A reaction flask loses mass as carbon dioxide escapes. What does a faster decrease in mass indicate?
Carbon dioxide is being produced at a faster rate
Which change increases collision frequency without directly changing the activation energy?
Increasing the concentration of a reactant in solution
Why are some collisions between reactant particles unsuccessful even when the particles collide?
The collision may have insufficient energy or an unsuitable orientation
What does a horizontal section on a product-formed-against-time graph indicate?
The reaction has stopped producing more product
How does a catalyst affect the final amount of product in a reaction that goes to completion?
It reaches the same final amount more quickly but does not change that amount