Advertisements
Advertisements
प्रश्न
The time required for 10% completion of a first order reaction at 298 K is equal to that required for its 25% completion at 308 K. If the value of A is 4 × 1010 s−1. Calculate k at 318 K and Ea.
उत्तर
t = `2.303/"k"_1 log ["R"]_0/(90/100 ["R"]_0)`
t = `2.303/"k"_2 log ["R"]_0/(75/100 ["R"]_0)`
t = `2.303/"k"_1 log 10/9`,
t = `2.303/"k"_2 log 4/3`
`2.303/"k"_1 log 10/9 = 2.303/"k"_2 log 4/3`
`=> "k"_2/"k"_1 = (log(4/3))/(log(10/9))`
= `log 1.333/log 1.111`
= `0.1249/0.0457`
= 2.733
log`"k"_2/"k"_1 = E_a/(2.303"R")(("T"_2 - "T"_1)/("T"_1"T"_2))`
⇒ log 2.733 = `E_a/(2.303 xx 8.314) ((308 - 298)/(298 xx 308))`
Ea = `(2.303 xx 8.314 xx 308 xx 298)/10 xx 0.4367`
= `(19.147 xx 308 xx 298)/10 xx 0.4367`
= 76.75 kJ mol−1
ln k = ln A `- E_a/("RT")`
log k = log A `- E_a/(2.303 "RT")`
= log (4 × 1010) `- (76.75 xx 1000)/(2.303 xx 8.314 xx 318)`
= 10.6021 `- 76750/6088.791`
= 10.6021 − 12.6051
= −2.003
k = Antilog (−2.003) = 9.93 × 10−3
APPEARS IN
संबंधित प्रश्न
Sucrose decomposes in acid solution into glucose and fructose according to the first order rate law with `"t"_(1/2)`= 3 hours. What fraction of the sample of sucrose remains after 8 hours?
A first order reaction has a rate constant 1.15 × 10−3 s−1. How long will 5 g of this reactant take to reduce to 3 g?
Time required to decompose SO2Cl2 to half of its initial amount is 60 minutes. If the decomposition is a first order reaction, calculate the rate constant of the reaction.
The following data were obtained during the first order thermal decomposition of SO2Cl2 at a constant volume.
\[\ce{SO2Cl2_{(g)} -> SO2_{(g)} + Cl2_{(g)}}\]
| Experiment | Time/s–1 | Total pressure/atm |
| 1 | 0 | 0.5 |
| 2 | 100 | 0.6 |
Calculate the rate of the reaction when total pressure is 0.65 atm.
For the decomposition of azoisopropane to hexane and nitrogen at 543 K, the following data are obtained.
| t (sec) | P(mm of Hg) |
| 0 | 35.0 |
| 360 | 54.0 |
| 720 | 63.0 |
Calculate the rate constant.
Following data are obtained for reaction :
N2O5 → 2NO2 + 1/2O2
| t/s | 0 | 300 | 600 |
| [N2O5]/mol L–1 | 1.6 × 10-2 | 0.8 × 10–2 | 0.4 × 10–2 |
1) Show that it follows first order reaction.
2) Calculate the half-life.
(Given log 2 = 0.3010, log 4 = 0.6021)
A first order reaction takes 20 minutes for 25% decomposition. Calculate the time when 75% of the reaction will be completed.
(Given : log = 2 = 0·3010, log 3 = 0·4771, log 4 = 0·6021)
Straight line graph for first order reaction is obtained between ____________.
A first order reaction is 50% completed in 1.26 × 1014 s. How much time would it take for 100% completion?
State a condition under which a bimolecular reaction is kinetically first order reaction.
The rate constant of a first order reaction is 6.9 × 10–3s–1. How much time will it take to reduce the initial concentration to its 1/8th value?
First order reaction is 50% complete in 1.26 × 1014s. How much time could it take for 100% completion?
In the first order reaction, half of the reaction is complete in 100 seconds. The time for 99% of the reaction to occurs will be
The reaction X → product
Follow first order of kinetics. In 40 minutes the concentration of 'X' changes from 0.1 m to 0.025. M. The rate of reaction when concentration of X is 0.01 m is.
Time required to decompose SO2Cl2 to half of its initial concentration is 60 minutes. If the de-composite is a first order reaction, calculated the rate constant of the reaction-
In a first order reaction the concentration of reactants decreases from 400mol L-1 to 25 mol L-1 in 200 seconds. The rate constant for the reaction is ______.
The reaction \[\ce{SO2Cl2(g) -> SO2(g) + Cl2(g)}\] is a first-order gas reaction with k = 2.2 × 10−5 sec−1 at 320°C. The percentage of SO2Cl2 is decomposed on heating this gas for 90 min, is ______%.
Write the unit of rate constant [k] for the first order reaction.
