Question

A reaction is 50%complete in 2 hrs and 75% complete in 4 hrs.What is the order of the reaction?(urgent )

Answer 1

1st order reaction..
 A goes down by 50% in the 1st 2hrs.

That is halved to 25% in the next 2 hrs.

The half - life is a constant 2hrs so the reaction must be 1st order.

Answer 2

Answer: 1

Explanation:

The time taken for nth fraction of a reaction of ist order reaction:

$t\frac{1}{n}=\frac{2.303}{k}\times \log \frac{n}{n-1}$

$t_{1/2}=\frac{2.303}{k}\times \log \frac{2}{2-1}$

$t_{1/2}=\frac{2.303}{k}\times \log 2$

$t_{3/4}=\frac{2.303}{k}\times \log \frac{4/3}{4/3-1}$

$t_{3/4}=\frac{2.303}{k}\times \log 4$

Thus $\frac{t_{3/4}}{t_{1/2}}=2$

Given : $\frac{t_{3/4}}{t_{1/2}}=\frac{4}{2}=2$

Thus order of the reaction is 1.