contestada

The rate constant k for a certain reaction is measured at two different temperatures:

temperature k

376.0 °c 4.8 x 108

280.0 °C 2.3 x 10 8

Assuming the rate constant obeys the Arrhenius equation, calculate the activation energy Ea for this reaction.

Round your answer to 2 significant digits.

Respuesta :

Answer:

Ea=5.5 Kcal/mole

Explanation:

Let rate constant are [tex]K_1[/tex]  and [tex]K_2[/tex]  at temperature [tex]T_1[/tex]  and [tex]T_2[/tex]

By using Arrhenius equation at two different two different temperature,

[tex]Log K_1/K_2 =E_a/2.303R*(1/T_2 -1/T_2 );T_1=273+376=649K ;K_1=4.8*10^8;T_2=273+280=553K ;K_2=2.3*10^8;R=2 cal/(mole.K);Log (4.8*10^8)/(2.3*10^8 )=E_a/2.303R*(1/553K-1/649); Log 4.8/2.3=E_a/2.303R*96/358897 ;0.32=E_a/2.303R*96/358897;E_a=(0.32*2.303R*358897)/96;[/tex]  

By putting value of R=2 cal/mole.K

[tex]E_a=5510.265cal/mole;[/tex]

By rounding off upto 2 significant figure;

[tex]E_a=5.5Kcal/mole;[/tex]

Otras preguntas