Question

For the decomposition of nitroglycerine, what is the average rate constant for the experiment with an initial concentration of 5.33 M and 34.6% decomposition after 180 seconds?

a) 2.0×10−3s−1
b) 1.0×10−3s−1
c) 3.0×10−3s−1
d) 4.0×10−3s−1

Answer 1

The average rate constant for the decomposition of nitroglycerine can be calculated using the first-order reaction formula, considering the initial concentration and the percentage of decomposition over a given time.

Step-by-step explanation:

To calculate the average rate constant for the decomposition of nitroglycerine at an initial concentration of 5.33 M with 34.6% decomposition after 180 seconds, we can use the formula for first-order reactions: k = ln([A]0/[A]) / t, where [A]0 is the initial concentration, [A] is the concentration of the reactant remaining after time t, and k is the rate constant.

Since 34.6% of the nitroglycerine decomposed, the remaining concentration of nitroglycerine after 180 seconds is 65.4% of the original, which is equal to 0.654 × 5.33 M. By substituting the values into the formula and solving for k, we would determine the correct rate constant value.