Integrated Rate Law Calculations: 1st Order

Question

The decomposition of nitramide in aqueous solution at 25°C

NH,NO₂(aq)

N₂O(g) + H₂O(I)

is first order in NH₂NO2 with a rate constant of 0.0000470 ¹.

If the initial concentration of NH2NO2, is 0.800 M, the concentration of NH2NO2 will be _____M after 29580.0 s have passed.

Answer 1

For a first order reaction, you can use ln [A] = -kt + ln [A]_o

[A] = ?

k = 0.0000470 s^-1

t = 29580 s

[A]_o = 0.800

Substitute and solve for [A]...

ln [A] = - (0.0000470)(29580) + ln (0.800) = -1.39 + - 0.223 = -1.613

[A] = 0.199 M