The half - life of N2O5 at 45 °C is 24 minutes. How long will it take for sample of N2O5 to decay to 25% of its original concentration?
Correct answer: D. 48 minutes
- A. 24 minutes
- B. 120 minutes
- C. 72 minutes
- D. 48 minutes
Explanation
First, find out how many half-lives it takes to reach 25% (which is 1/4) of the original concentration:- (¼) = 2 , where 'n' is the number of half-lives.(-n) Taking the logarithm of both sides:-n = log(¼) / log(2) n = log(4) / log(2) = 2Since it takes 2 half-lives to reach 25% of the original concentration, you can multiply the half-life by 2 to find the total time required:Total time = 2 * 24 minutes = 48 minutes.
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Reaction kinetics relates reaction rate to concentration, temperature, surface area and catalysts. Questions cover rate laws, reaction order, rate constants, activation energy and the activated complex, including how a catalyst lowers the activation energy without changing the overall energy change or equilibrium position.
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