You visited us 1 times! Enjoying our articles? Unlock Full Access!

Byju's Answer

Standard XII

Chemistry

Ellingham Diagram

The rate cons...

Question

The rate constants for decomposition of acetaldehyde have been measured over the temperature range $700 - 1000 K$ . The data has been analysed by plotting In k vs $\frac{10^{3}}{T}$ graph. The
value of activation energy for the reaction is
$k J m o l^{- 1}$ (Nearest integer)
$(Given: R = 8.31 J K^{- 1} m o l^{- 1})$

Open in App

Solution

In $k = ln A - \frac{E_{a}}{R T}$
$∴ Slope of the graph = - \frac{E_{a}}{R \times 10^{3}} = - 18.5$
$∴ E_{a} = 18.5 \times 8.31 \times 1000 = 154 k J m o l^{- 1}$

Suggest Corrections

Similar questions

Q. The rate constant

(k)

of a reaction is measured at different temperatures

(T)

, and the data are plotted in the given figure. The activation energy of the reaction in

k J m o l^{- 1}

is:
Here,

R

is gas constant :

The first order rate constant for the decomposition of ethyl iodide by the reaction:

$C_{2} H_{5} I (g) \to C_{2} H_{4} (g) + H I (g)$

at $600 K$ is $1.60 \times 10^{- 5} s^{- 1}$ . Its energy of activation is $209 k J m o l^{- 1}$ . The rate constant of the reaction at $700 K$ will be:

Q. It has been found that for a chemical reaction with rise in temperature by

9 K

the rate constant gets doubled. Assuming a reaction to be occurring at

300 K,

the value of activation energy is found to be _______

k J m o l^{- 1} .

[nearest integer]
(Given

l n 10 = 2.3, R = 8.3 J K^{- 1} m o l^{- 1}, log 2 = 0.30)

Q. Rate constant

k

of a reaction varies with temperature according to the equation

log k = c o n s t a n t - \frac{E_{a}}{2.303 R} \times \frac{1}{T}

where

E_{a}

is the energy of activation for the reaction. When a graph is plotted for

log k

\frac{1}{T}

a straight line with a slope

- 6670 k

is obtained. The activation energy for this reaction will be:

(

R = 8.314 J K^{- 1} {m o l}^{- 1})

Q. The first order rate constant for the decomposition of

C a C O_{3}

700 K

6.36 \times 10^{- 3} s^{- 1}

and activation energy is

209 k J {mol}^{- 1}

. Its rate constant (in

s^{- 1}

) at

600 K is X \times 10^{- 6}

. The value of is (Nearest integer)
[Given

R = 8.31 J K^{- 1} {mol}^{- 1}; log 6.36 \times 10^{- 3} = - 2.19, 10^{- 4.79} = 1.62 \times 10^{- 5}

Join BYJU'S Learning Program

The rate constants for decomposition of acetaldehyde have been measured over the temperature range 700−1000 K. The data has been analysed by plotting In k vs 103T graph. The value of activation energy for the reaction is kJ mol−1 (Nearest integer) (Given: R = 8.31 JK−1mol−1)

In k=lnA−EaRT ∴Slope of the graph=−EaR×103=−18.5 ∴Ea=18.5×8.31×1000=154 kJ mol−1

In $k = ln A - \frac{E_{a}}{R T}$
$∴ Slope of the graph = - \frac{E_{a}}{R \times 10^{3}} = - 18.5$
$∴ E_{a} = 18.5 \times 8.31 \times 1000 = 154 k J m o l^{- 1}$