Rate Of Reactions Flashcards
(8 cards)
Define the rate of a chemical reaction.
The rate of a chemical reaction refers to the speed at which a reactant is being used up or the speed at which products are being formed.
What are the factors affecting the rate of reaction?
- Concentration
- Particle Size of Reactants
- Temperature
- Catalysts
- Pressure of gaseous reactants
Category: Factors affecting rate of reaction
How does an increase in concentration affect the rate of reaction?
An increase in concentration leads to an increase in the rate of reaction. When concentration increases, the number of particles per unit volume also increases. Thus the frequency of effective collisions increases between the reacting particles, and hence the rate of reaction increases.
Category: Factors affecting rate of reaction
How does increased pressure of gaseous reactants increase the rate of reaction?
At higher pressure, gaseous particles are compressed closer to one another, hence there are more particles per unit volume. Therefore, the frequency of effective collisions increases between the reacting particles, thus the rate of reaction increases.
Category: Factors affecting rate of reaction
How does particle size of the reactants affect the rate of reaction?
When the size of the reacting particle decreases, the surface area to volume ratio increases, meaning that the frequency of effective collisions between reacting particles, thus the rate of reaction increases.
Category: Factors affecting rate of reaction
How does temperature affect the rate of reaction?
The greater the temperature, the greater the kinetic energy of the particles, thus they move faster and more particles possess energy that is greater than or equal to the activation energy, and the frequency of effective collisions between particles also increases, hence the rate of reaction increases.
Category: Factors affecting rate of reaction
How do catalysts increase the rate of reaction?
Catalysts provide an alternative pathway for reactants with lower activation energy. Thus, more particles possess energy greater than or equal to the lowered activation energy. As such, the frequency of effective collisions between particles increases, and the rate of reaction increases. Side note: A catalyst does not affect the amount of products formed; catalysts merely increase the rate of reaction, and as such do not affect equilibrium position.
Category: Factors affecting rate of reaction
