Question

Consider two reactions. Reaction (1) has a constant half-life, whereas reaction (2) has a half-life that gets longer as the reaction proceeds. Part A What can you conclude about the rate laws of these reactions from these observations? What can you conclude about the rate laws of these reactions from these observations? The first reaction is a first order reaction, the second one should have an order greater than first. The first reaction should have a first or a second order, the second one should have an order greater than second. The first reaction should have a first or a second order, the second one should have an order not less than second. The first reaction is a first order reaction, the second one has a second order.

Answer 1

Hey there!

write expressions for half-life of zero to third order reaction:

* zero order :

t(1/2) = 0.5 [A]₀ / K

* first order :

t(1/2) = 0.693 / K

* second order:

t(1/2) = 1 / K[A]₀

* third order :

t(1/2) = 3 / K[A]₀²

From observation , we can conclude that half-life for first order reactions is constants. Whereas , half-life increases With decrease in [A]₀ or as reaction proceeds , for reactions of order more than 1 st , therefore :

The first reaction is a first order reaction, the second one should have an order greater than first.

Answer A

Hope that helps!