#1
Which of the following factors can affect the reaction rate?
All of the above
ExplanationVarious factors, including concentration, temperature, and catalyst presence, can influence reaction rates.
#2
What is the role of a solvent in chemical reactions?
To dissolve the reactants and products
ExplanationSolvents facilitate the dissolution of reactants and products, aiding in chemical reactions.
#3
What does the term 'reaction rate' refer to in chemical kinetics?
The speed at which reactants are consumed
ExplanationReaction rate measures the rate at which reactants are transformed into products.
#4
Which order of reaction represents a constant reaction rate over time?
Zero order
ExplanationIn a zero-order reaction, the rate remains constant regardless of reactant concentration changes.
#5
What is the collision theory in chemical kinetics?
It describes the collision of reactant molecules leading to a chemical reaction
ExplanationThe collision theory explains how reactant collisions lead to successful chemical reactions.
#6
Which factor does not typically affect the rate of a zero-order reaction?
Concentration of reactants
ExplanationIn zero-order reactions, changing reactant concentrations has no impact on the reaction rate.
#7
Which factor is most likely to affect the reaction rate of a heterogeneous reaction?
Catalyst presence
ExplanationIn heterogeneous reactions, catalysts play a significant role in influencing reaction rates.
#8
What is the order of a reaction if changing the concentration of one reactant has no effect on the overall reaction rate?
Zero order
ExplanationIn zero-order reactions, altering the concentration of one reactant does not impact the overall reaction rate.
#9
What is the primary purpose of a reaction mechanism in chemical kinetics?
To study the intermediate steps of a reaction
ExplanationReaction mechanisms provide insights into the step-by-step processes and intermediates involved in a chemical reaction.
#10
What is the half-life of a first-order reaction?
0.693/k
ExplanationThe half-life of a first-order reaction is inversely proportional to the rate constant (k).
#11
What is the role of a catalyst in a chemical reaction?
It lowers the activation energy
ExplanationCatalysts decrease the energy barrier for reactions, facilitating faster reaction rates.
#12
What is the Arrhenius equation used for in chemical kinetics?
To determine the activation energy of a reaction
ExplanationThe Arrhenius equation helps calculate the activation energy required for a chemical reaction.
#13
In a reaction A + B → C, if the concentration of B is doubled, how does it affect the reaction rate if the reaction is first-order with respect to B?
The rate doubles
ExplanationFor a first-order reaction, doubling the concentration of B leads to a proportional doubling of the reaction rate.
#14
What is the relationship between reaction rate and temperature, according to the Arrhenius equation?
Exponential
ExplanationAccording to the Arrhenius equation, the relationship between reaction rate and temperature is exponential.
#15
How does an increase in the activation energy of a reaction affect the rate constant?
Decreases
ExplanationHigher activation energy leads to a lower rate constant, slowing down the reaction.
#16
What is the rate-determining step in a chemical reaction mechanism?
The step with the highest activation energy
ExplanationThe rate-determining step has the highest activation energy, governing the overall reaction rate.