Question

The rate at which tree crickets chirp is 1.80 * 10^2 per minute at 28 C but only 42.8 per minute at 6.5 degrees. From these data, calculate the activation energy for the chirping process.

Answer 1

Answer:

Activation energy is 42.65kJ

Explanation:

Formula for activation energy is

In(k2/k1)=-Ea/k(1/t2- 1/t1)

In(42.8/180)= -Ea/8.314(1/279.5-1/301)

-1.4364 x 8.314=-Ea (0.00028)

Ea=42651.37

Ea=42.65kJ

Answer 2

Answer:

$46.750\frac{KJ}{mol}$

Explanation:

To calculate the activation energy for the chirping process, let's first state our given parameters.

Given that:

K₂ = 1.8 × 10² chirp/min at 28°C (301 K)    &

K₁ = 42.8 chirp/min at 6.5°C ( 279.5 K)

The formula for calculating activation energy is given by;

$In[ \frac{K_2}{K_1}] = -\frac{E_a}{R} [{\frac{1}{T_2}-\frac{1}{T_1}]$

$In[ \frac{1.8*10^2 chirp/min}{42.8 chirp/min}] = -\frac{E_a}{8.314J/mol/K} [{\frac{1}{301K}-\frac{1}{279.5K}]$

$In 4.206 = \frac{E_a}{8.314 J/mol/K}[\frac{21.5}{279.5*301K}]$

$E_a=\frac{8.314J/mol/k*1.437*279.5*301K}{21.5}$

     $=\frac{1005113.477}{21.5}$

     $= 46749.46 mol$

     $=46.750\frac{KJ}{mol}$