# Rate Constant - My Work is Incorrect

posted by .

Hi! I am stuck with this question and I would like to know what I did wrong:

Given that the initial rate constant is 0.0160 s-1 at an initial temperature of 25 degrees C, what would the rate constant be at a temperature of 130 degrees C for the same reaction described in Part A?

I solved for the Ea, and I got 32,900 J.
ln(k2/k1) = (Ea/R)(1/T1 - 1/T2)
ln(k2/0.0160) = (32,900/8.314)(1/298.15 - 1/314.55)
ln(k2/0.0160) = (3,957.180)(0.00174871)
ln(k2/0.0160) = (0.6919986)
(k2/0.0160) = e^(0.6919986)
(k2/0.0160) = 1.997704
k2 = 0.03196

The answer above is not correct.

Thanks!

• Rate Constant - My Work is Incorrect -

ln(k2/k1) = (Ea/R)(1/T1 - 1/T2)
The equation is OK

ln(k2/0.0160) = (32,900/8.314)(1/298.15 - 1/314.55)
All of the substitutions look ok except for T2. 273.15 + 130 C = 403.15 and not 314.15.

ln(k2/0.0160) = (3,957.180)(0.00174871)
ln(k2/0.0160) = (0.6919986)
(k2/0.0160) = e^(0.6919986)
(k2/0.0160) = 1.997704
k2 = 0.03196

With the corrected T2 I obtained k2 = 0.5074.
This is the same problem I did yesterday, I think, EXCEPT the problem then was to calculate T2 when k was doubled. This is just the reverse, so of course, you obtained 0.032 for k2 which is just double k1 when you substituted the T2 we calculated. If this k2 (0.5074 to the right number of significant figures) is not right, the problem may be the Ea. Since that came from another problem (at least it appears that way from your presentation) that could be the culprit. Hope this helps.

## Similar Questions

1. ### Chemistry

The reaction X + Y --> products was studied using the method of initial rates. The initial rate of consumption of X was measured in three different experiments. What is the value of the rate constant, k?
2. ### Chemistry

Given that the initial rate constant is 0.0190s^-1 at an initial temperature of 20 degrees Celsius, what would the rate constant be at a temperature of 170 degrees Celsius?
3. ### Chemistry

Your Open Question Show me another » Chemistry help needed... Confused?
4. ### Arrhenius Reaction

The activation energy of a certain reaction is 32.9 kJ/mol At 25 degrees C the rate constant is 0.0160 units s-1 units. At what temperature in degrees Celsius would this reaction go twice as fast?
5. ### Arrhenius Question

The activation energy of a certain reaction is 32.9 kJ/mol At 25 degrees C the rate constant is 0.0160 units s-1 units. At what temperature in degrees Celsius would this reaction go twice as fast?
6. ### Temperature and Rate

Q: The activation energy of a certain reaction is 32.9 kJ/mol At 25 degrees C the rate constant is 0.0160 units s-1 units. At what temperature in degrees Celsius would this reaction go twice as fast?
7. ### How to Set Up Equation

Given that the initial rate constant is at an initial temperature of 25 degrees C, what would the rate constant be at a temperature of 130 degrees C for the same reaction described in Part A?
8. ### Chemistry

Given that the initial rate constant is 0.0190s^-1 at an initial temperature of 20 degrees Celsius, what would the rate constant be at a temperature of 170 degrees Celsius?
9. ### Chemistry

Given that the initial rate constant is 0.0190s−1 at an initial temperature of 22 ∘C , what would the rate constant be at a temperature of 190 ∘C for the same reaction described in Part A?
10. ### Chemistry

A student tested the effect of temperature on the decomposition of N2O5. He found that the rate of the reaction at a lower temperature was 4.2 x 10–3 s–1 and the rate at a higher temperature was 1.6 x 101 s–1. What is wrong with …

More Similar Questions