Hello, I have three Chemistry problems I have to study for a quiz but she didn't really go over them well. I can't go to her for help on them since the test is next class and well.. it's the weekend. Everything else in the chapter I know fine but can't seem to derive these from the equations correctly. I just got an answer almost correct on one.. but almost is still wrong.



1.X has a half-life of 36.00s. Determine the time needed for the reaction to be 62.0% complete if the starting concentration is 12.60M

2. [A] reaction is found to have an activation energy of 108 kj/mol. If the rate constant for this reaction is (4.60x10^-6) at 275 K, what is the rate constant at 366 K?

3. The second-order decomposition of NO2 has a rate constant of 0.255 M/s. How much NO2 decomposes in 4.00s if the initial concentration of NO2 (1.00L volume) is 1.33M?

1.X has a half-life of 36.00s. Determine the time needed for the reaction to be 62.0% complete if the starting concentration is 12.60M
is this reaction first order kinetics?
Then first work out k value using equation
k= ln2/half life
Then use ln[A] = -kt+ ln[A]0
[A]0 = 12.60M
[A]  = 12.60- 62.0% of 12.60M
plug in above equation and get  time
[A] reaction is found to have an activation energy of 108 kj/mol. If the rate constant for this reaction is (4.60x10^-6) at 275 K, what is the rate constant at 366 K?
Use Arrhenius equation

3. The second-order decomposition of NO2 has a rate constant of 0.255 M/s. How much NO2 decomposes in 4.00s if the initial concentration of NO2 (1.00L volume) is 1.33M?
Use integrated rate law
1/[A]= kt + 1/[A]o