Question

Experimental data for the reaction A → 2B + C have been plotted in the following three different ways (with concentration units in mol/L). a) Determine the rate constant. b) Calculate the equilibrium constant. c) Find the order of the reaction. d) Identify the reaction mechanism.

Answer 1

To address a student's chemistry question, the rate constant is found using reaction rates and concentration changes, the equilibrium constant is calculated from equilibrium concentration expressions, the order of a reaction is determined through dependency on concentrations, and the reaction mechanism is deduced from the kinetics and intermediate steps.

Step-by-step explanation:

Determining Rate Constant, Equilibrium Constant, Order of Reaction, and Reaction Mechanism

To determine the rate constant (k) for the reaction A → 2B + C, one would typically need experimental data illustrating the concentration of reactants and products over time. By comparing initial reaction rates with changes in concentration, one can infer whether the reaction follows a zeroth, first, or second-order rate law. Once the order is determined, the rate law can be written, and k can be solved using data from the experiments.

The equilibrium constant (Kc) for a reaction can be calculated if the reaction is at equilibrium. For the given equation A(aq) + 2B(aq) ⇒ 2C(aq), Kc is calculated using the expression Kc = [C]^2 / ([A][B]^2), where the concentrations are those at equilibrium. If given specific equilibrium concentrations, these could be plugged into the equilibrium expression to verify Kc or solve for missing concentrations.

The order of reaction is determined by examining how varying the concentrations of reactants affects the rate of reaction. If the rate does not change with concentration changes, the reaction is zeroth-order concerning that reactant. If the rate changes proportionately with concentration it is first-order, and if it changes with the square of concentration, it is second-order.

Identifying the reaction mechanism typically involves more detailed kinetic studies and sometimes requires looking at intermediate species formation and their respective rates. Experimentally, mechanisms are often elucidated by analyzing the rate laws and comparing them against proposed mechanisms until the data fits a plausible sequence of elementary steps consistent with the overall reaction.

Answer 2

The provided question asks for the determination of various aspects of a reaction based on experimental data: rate constant, equilibrium constant, order of the reaction, and the reaction mechanism.

Step-by-step explanation:

The given question is asking us to determine various aspects of a reaction based on experimental data. Let's break down each part:

a) To determine the rate constant, we need to calculate the initial rates of reaction for different concentrations of A and B. By comparing the initial rates with the concentrations, we can find the rate constant using the rate law equation.

b) The equilibrium constant can be calculated by using the concentrations of the reactants and products at equilibrium. Since the reaction is A → 2B + C, the equilibrium constant expression would be Kc = [B]^2[C]/[A].

c) To find the order of the reaction, we need to compare the changes in initial concentrations with the corresponding changes in rates of reaction for each species. By analyzing the rate law, we can determine the order of the reaction.

d) Identifying the reaction mechanism requires additional information about the reaction and its intermediates. Without that information, it is not possible to determine the specific mechanism of the reaction.