Question

The rate constant for the decomposition of nitrogen dioxide NO₂(g) --> NO(g) + 1/2 O₂(g) with a laser beam is 1.4 1/m min. find the time, in seconds, needed to decrease 2.39 m of NO₂ to 0.99 m. hint: what is the order of the reaction?

Answer 1

To find the time needed to decrease 2.39 mol of NO₂ to 0.99 mol, we need to determine the order of the reaction and use the rate equation. The time required is 21 seconds.

Step-by-step explanation:

To find the time needed to decrease 2.39 mol of NO₂ to 0.99 mol, we need to first determine the order of the reaction.

By using the given rate constant of 1.4 1/m min, we can set up the rate equation for the reaction:

Rate = k[NO₂]

Since the rate constant is given in 1/m min, the reaction must be first order with respect to NO₂. So the rate equation becomes:

Rate = k[NO₂]

Now we can use the rate equation to find the time needed to decrease the concentration from 2.39 mol to 0.99 mol. Rearranging the rate equation, we have:

t = (ln([NO₂]₀/[NO₂])) / k

Substituting the values, we get:

t = (ln(2.39/0.99)) / 1.4

t = 0.350 min

Converting to seconds:

t = 0.350 min * 60 s/min = 21 s