1 Flashcards
(55 cards)
What is the rate of a chemical reaction?
The speed or rate at which reactants are converted into products in a chemical reaction
It can be affected by factors such as concentration, temperature, pressure, and the presence of a catalyst.
What factors can affect the rate of a chemical reaction?
- Concentration
- Temperature
- Pressure
- Presence of a catalyst
These factors can alter the speed at which reactions occur.
What is the difference between average and instantaneous rates of reaction?
Average rate is calculated over a time interval, while instantaneous rate is the rate at a specific moment in time
Average rate gives a general speed, while instantaneous rate provides a precise measurement.
Give an example of a fast chemical reaction.
Precipitation of silver chloride by mixing aqueous solutions of silver nitrate and sodium chloride
This reaction occurs instantaneously.
Give an example of a slow chemical reaction.
Rusting of iron in the presence of air and moisture
This process takes a significant amount of time to occur.
What is the mathematical expression for the rate of reaction in terms of concentration?
Rate = Change in concentration of reactant or product per unit time
This can be expressed as the rate of disappearance of reactants or the rate of appearance of products.
What do the square brackets in the expressions for concentration represent?
Molar concentration of reactants and products
For example, [R] indicates the concentration of reactant R.
In a hypothetical reaction, what does one mole of reactant R produce?
One mole of product P
This is a basic stoichiometric relationship in chemical reactions.
Fill in the blank: The rate of disappearance of reactant R is measured as _______.
the change in concentration of R over time
This is crucial for calculating the overall reaction rate.
True or False: The rate of a reaction can vary depending on the conditions under which it occurs.
True
Different conditions such as temperature and concentration can significantly alter the reaction rate.
What is a collision theory in the context of reaction rates?
A theory that explains how the orientation and energy of molecules during collisions affect the rate of reaction
This theory helps in understanding the mechanisms behind chemical reactions.
What is chemical kinetics?
The study of the rates of chemical reactions and the factors affecting them.
True or False: The rate of a reaction is constant throughout the reaction.
False
What factors affect the rate of a chemical reaction?
Concentration, temperature, surface area, and the presence of catalysts.
Fill in the blank: The rate of reaction increases with an increase in ___.
temperature
Define ‘reaction rate’.
The change in concentration of a reactant or product per unit time.
What is the unit of reaction rate?
mol L^-1 s^-1
How does concentration affect the rate of reaction?
Increasing the concentration of reactants generally increases the reaction rate.
What is the role of a catalyst in a chemical reaction?
A catalyst increases the rate of a reaction without being consumed in the process.
True or False: Catalysts change the equilibrium constant of a reaction.
False
What does the rate law expression represent?
The relationship between the rate of a reaction and the concentration of its reactants.
What is the general form of a rate law expression?
Rate = k[A]^m[B]^n
Define the term ‘order of reaction’.
The sum of the powers of the concentration terms in the rate law.
What is zero-order reaction?
A reaction whose rate does not depend on the concentration of reactants.
