Question

A chemistry experiment was conducted to determine the rate constant for the reaction between hydrogen peroxide and iodide ion in acidic medium. The initial concentrations of hydrogen peroxide and iodide ion were 0.2 M and 0.1 M respectively. The reaction was carried out at 25°C and the time taken for the completion of the reaction was 60 seconds. Based on these data, what is the rate constant for the reaction?

Answer 1

To determine the rate constant for the reaction, we need to know the order of the reaction. Let's assume it is a first-order reaction. For a first-order reaction, the rate law is given by:Rate = k[A]^1where Rate is the reaction rate, k is the rate constant, and [A] is the concentration of the reactant.Since the reaction is completed in 60 seconds, we can assume that the concentration of hydrogen peroxide  [H2O2]  decreases from 0.2 M to 0 M in that time. The rate of the reaction can be calculated as:Rate =  Final concentration - Initial concentration  / TimeRate =  0 M - 0.2 M  / 60 sRate = -0.2 M / 60 sRate = -0.00333 M/sNow, we can use the rate law to find the rate constant  k :Rate = k[H2O2]^1-0.00333 M/s = k 0.2 M k = -0.00333 M/s / 0.2 Mk = -0.01665 s^-1 However, the rate constant should be a positive value. Since we assumed a first-order reaction, it's possible that the reaction is not first-order. To accurately determine the rate constant, we would need more information about the reaction order or experimental data to analyze the reaction kinetics.