Podcast
Questions and Answers
What does the instantaneous rate of consumption of a reactant represent?
What does the instantaneous rate of consumption of a reactant represent?
- The total amount of reactant consumed
- The change in concentration of the product over time
- The total change in mass during a reaction
- The change in concentration of a reactant over time (correct)
In the reaction A + 2B → 3C + D, how is the rate of formation of product D expressed?
In the reaction A + 2B → 3C + D, how is the rate of formation of product D expressed?
- Equal to the rate of consumption of A
- Half the rate of consumption of A
- Twice the rate of consumption of B
- One-third the rate of formation of C (correct)
If the rate of formation of 2NO is 0.16 mmol dm-3 s-1, what is the rate of consumption of NOBr?
If the rate of formation of 2NO is 0.16 mmol dm-3 s-1, what is the rate of consumption of NOBr?
- 0.64 mmol dm-3 s-1
- 0.16 mmol dm-3 s-1 (correct)
- 0.08 mmol dm-3 s-1
- 0.32 mmol dm-3 s-1
What is the rate of formation of CH3CH3 if the rate of change of CH3 radicals is -1.2 mol dm-3 s-1?
What is the rate of formation of CH3CH3 if the rate of change of CH3 radicals is -1.2 mol dm-3 s-1?
What is the general form of a rate law for a reaction?
What is the general form of a rate law for a reaction?
In the ionic form of the reaction Mg(s) + 2HCl(aq) → H2(g) + MgCl2(aq), what type of ion is Cl- considered?
In the ionic form of the reaction Mg(s) + 2HCl(aq) → H2(g) + MgCl2(aq), what type of ion is Cl- considered?
Which of the following statements regarding stoichiometry is true for A + 2B → 3C + D?
Which of the following statements regarding stoichiometry is true for A + 2B → 3C + D?
Which term describes the rate at which the concentration of a reactant decreases over time?
Which term describes the rate at which the concentration of a reactant decreases over time?
What represents the order of reaction with respect to a species in a rate law?
What represents the order of reaction with respect to a species in a rate law?
What is the overall order of a reaction with the rate law $v = k[A]^{1/2}[B]$?
What is the overall order of a reaction with the rate law $v = k[A]^{1/2}[B]$?
What does a zero-order rate law imply about the reaction rate?
What does a zero-order rate law imply about the reaction rate?
In the pseudo first-order rate law, what is approximated as constant?
In the pseudo first-order rate law, what is approximated as constant?
If a reaction has the rate law $v = k[A]^{m}[B]^{n}$, how are m and n characterized?
If a reaction has the rate law $v = k[A]^{m}[B]^{n}$, how are m and n characterized?
What does the rate constant (k) depend on?
What does the rate constant (k) depend on?
What is true about individual reaction orders in a rate law?
What is true about individual reaction orders in a rate law?
What is the significance of determining a rate law experimentally?
What is the significance of determining a rate law experimentally?
What does the method of initial rates measure?
What does the method of initial rates measure?
What does the slope of the plot of log vo against log [I]o indicate?
What does the slope of the plot of log vo against log [I]o indicate?
If the order of reaction with respect to Ar is one, how does this affect the rate law?
If the order of reaction with respect to Ar is one, how does this affect the rate law?
What is the initial rate law derived from the given slopes in the problem?
What is the initial rate law derived from the given slopes in the problem?
What does the intercept of the plot of log vo against log [I]o represent?
What does the intercept of the plot of log vo against log [I]o represent?
How are the orders of reaction determined for both I and Ar?
How are the orders of reaction determined for both I and Ar?
If the concentration of I doubles, how does the rate change if the order is two?
If the concentration of I doubles, how does the rate change if the order is two?
What type of function is expected when plotting log vo against log [A]o?
What type of function is expected when plotting log vo against log [A]o?
Flashcards are hidden until you start studying
Study Notes
Rate of Reaction
- The rate of reaction is the change in concentration of a reactant or product over time.
- The rate of consumption of a reactant is a positive quantity.
- The rate of formation of a product is also a positive quantity.
- The stoichiometry of the reaction dictates the relationship between the rates of consumption and formation of different reactants and products.
- For example, in the reaction A + 2B → 3C + D, the rate of formation of C is three times the rate of consumption of A.
- The rate of reaction can be expressed in terms of molar concentration, molecules per cubic centimeter, or other appropriate units.
Rate Laws and Rate Constants
- The rate law is an equation that describes the rate of a reaction as a function of the concentrations of the reactants.
- The rate constant is a proportionality constant in the rate law that reflects the intrinsic rate of the reaction.
- The rate law is determined experimentally and cannot be predicted from the stoichiometry of the reaction.
- The reaction order with respect to a particular reactant is the exponent to which its concentration is raised in the rate law.
- The overall order of a reaction is the sum of the individual orders with respect to each reactant.
Determining the Rate Law
- Isolation Method: This method involves keeping the concentrations of all reactants except one constant, allowing for the determination of the order of reaction with respect to the isolated reactant.
- The rate law can then be approximated by the pseudo-first-order rate law.
- Method of Initial Rates: This method involves measuring the initial rate of reaction for different initial concentrations of reactants.
- By analyzing the relationship between initial rates and initial concentrations, the reaction orders and the rate constant can be determined.
Example: Recombination of Iodine Atoms
- The reaction of iodine atoms in the presence of argon is an example of a reaction whose rate law can be determined using the method of initial rates.
- The results of the experiment show that the reaction is second-order with respect to iodine atoms and first-order with respect to argon atoms.
- The rate constant for the reaction was determined to be 9 x 10^9 mol^-2 dm^3 s^-1.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
