Question

A reaction is 50% complete in 2 h and 75% complete in 4 h. What is the order of reaction?

Answer 1

Given:

50% complete in 2 h

75% complete in 4 h

To find: Order of reaction = ?

Calculations:

50% complete [A] = `[A]_0/2`at 2 hours

75% complete [A] = `[A]_0/2`at 4 hours

This means

From 0 to 2 h: [A]₀ → `[A]_0/2`

From 2 to 4 h: `[A]_0/2` → `[A]_0/4`

So, it takes another 2 h to halve again to from [A]₀/2  to [A]₀/4