For the reaction A → B the following graph was obtained. The time required (in seconds) for the concentration of A to reduce to 2.5 g L − 1 (if the initial concentration of A was 50 g L − 1 ) is _____

Question

For the reaction A → B the following graph was obtained. The time required (in seconds) for the concentration of A to reduce to 2.5 g L − 1 (if the initial concentration of A was 50 g L − 1 ) is _______ (Nearest integer) Given : lo g 2 = 0.3010 [We can assume in a hypothetical situation that the graph is correct, assuming its first order reaction, in reality the question is wrong.]

TestHub · Accepted Answer

As it is difficult to predict order using data provided in graph.
For specific time interval $0 - 5 sec, 5 - 10 sec$ and $10 - 15 sec$ . order comes to be zero, but graph is not a straight line.
Assuming $1^{st}$ order kinetics
$k = \frac{1}{t} ln \frac{A _{0}}{A _{t}} k = \frac{1}{10} ln \frac{40}{20}$
Time required to reduce to $2.5 g / L$
$k = \frac{1}{t} ln \frac{50}{2.5} \frac{1}{10} ln 2 = \frac{1}{t} ln 20 t = \frac{1.3010 \times 10}{0.3010} = 43.3 sec$

Chemistry - Chemical Kinetics Question with Solution | TestHub

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