textbook 7B #5

[Kaylee Nezwek 1D]

hey! for this question it says N2O5 decomposes first-order with k=0.15 at 353 K. part a asks for the half-life in seconds. I used the formula: half-life = 0.693/k and plugged in 0.15, but I got the wrong answer. does anyone know why this is wrong?

[Faaizah Arshad 1H]

It is asking for the half life in hours.
Use t = 0.693/k to find the half life in seconds and then divide by 3600 seconds to convert to hours.

[Giselle Granda 3F]

I'm not sure if you are referring to the right problem because the rate constant for 7B.5a says it is 3.7x10^-5 in the textbook. I simply plugged that into the first order half life equation and converted seconds into hours. Hope that helps!

[Astha Patel 2J]

The way you solved it is correct. I would double check units.