# chemistry

posted by .

follows first-order kinetics and has an activation energy of 244 kJ mol-1. At 684 K, k = 0.00000508 s-1. What is the half-life (min) for this reaction at 427 °C ? Round your answer to 3 significant figures.

I really don't know what to do

• chemistry -

You have k at one T (684) and you can calculate k at another T (427) with the Arrhenius equation. Then knowing it is first order, you can use
ln(No/N) = kt.
You can use any convenient number (such as 100) for No, use half that for N (50 if you use 100), plug in k at 427 (that's the T for which you want the 1/2 life), and solve for t. That will be the half-life because you have just 1/2 the number of atoms you started with.

## Similar Questions

1. ### Chemistry

Gallium65, a radioactive isotope of gallium, decays by first order-kinetics. The half-life of this isotope is 15.2 min. How long would it take for 7/8 of a sample of this isotope to decay?
2. ### CHEM- KINETICS

Dinitrogen tetraoxide, N2O4, decomposes to nitrogen dioxide, NO2, in a first-order process. If k = 2.5 x 103 s-1 at -5° Cand k = 3.5 x 104 s-1 at 25° C, what is the activation energy for the decomposition?
3. ### college chemistry

The rate of the following reaction: 2 NO2 2 NO + O2, is characterized by the rate constant k = 0.775 L·mol-1s-1. What is the half-life for this reaction at the same conditions when the initial concentrations are 0.0115 M?
4. ### Chemistry

The given reaction, 2N2O5 4NO2 + O2, follows first-order kinetics and has an activation energy of 103 kJ mol-1. At 298 K, k = 0.0000354 s-1. What is the half-life (min) for this reaction at 338 K ?
5. ### Chemistry

1. The reaction, CO(CH2COOH)2 CO(CH3)2 + 2CO2, follows first-order kinetics and has an activation energy of 96.6 kJ mol-1. At 293 K, k = 0.133 s-1. Find the temperature (in K) at which half-live will be 0.00692 min?
6. ### chemistry

The given reaction, cyclopropane propene (isomerization), follows first-order kinetics. The half-live was found to be 4.57 min at 796 K and rate constant was found to be 0.0328 s-1 at 850 K. Calculate the activation energy (in kJ/mol) …
7. ### chemistry

After 56.0 min, 25.0% of a compound has decomposed. What is the half-life of this reaction assuming first-order kinetics?
8. ### Chemistry

After 53.0 min, 14.0% of a compound has decomposed. What is the half-life of this reaction assuming first-order kinetics?
9. ### chemistry

If the breakdown half-life of a pesticide applied to a farmer’s field is 3.50 days, then what is the rate constant for this reaction?
10. ### Chemistry

After 62.0 min, 11.0% of a compound has decomposed. What is the half-life of this reaction assuming first-order kinetics?

More Similar Questions