(13.39) A reaction has a rate constant of 1.24×10−2 /s at 400. K and 0.689 /s...

(13.39) A reaction has a rate constant of 1.24×10⁻² /s at 400. K and 0.689 /s at 450. K.

1. Determine the activation barrier for the reaction.

2. What is the value of the rate constant at 425 K?

Solutions

Expert Solution

1. Determine the activation barrier for the reaction.

activation barrier or Ea also can be calculated from the values of k at only two temperatures by the formula;

ln(k2/k1) = Ea/R(1/T1 - 1/T2)

T1 = 400 K
k1 = 1.24 x 10^-2 s^-1

T2 = 450 K
k2 = 0.689 s^-1

R = 8.3145 J/K.mol (Gas constant)

ln(0.689 s^-1 / 1.24 x 10^-2 s^-1) = Ea / 8.3145 (1/400 - 1/450)

4.02 = Ea / 8.3145 (2.5*10^-3- 2.22*10^-3)

4.02 = Ea / 8.3145 (2.8 x 10^-4)
Ea = (4.02 x 8.3145) / 2.8 x 10^-4

= 1.2x 10^5 J/mol

2. What is the value of the rate constant at 425 K?

ln(k2- ln k1) = Ea/R(1/T1 - 1/T2)

T1 = 400 K
k1 = 1.24 x 10^-2 s^-1

T2 = 425 K
k2 = ? s^-1

R = 8.3145 J/K.mol (Gas constant)
Ea= 1.2x 10^5 J/mol

ln k2- ln1.24 x 10^-2 s^-1) = 1.2x 10^5 J/mol / 8.3145 (1/400 - 1/425)

ln k2+ 4.39 s^-1 = 1.2x 10^5 J/mol / 8.3145 (2.5*10^-3 -2.35*10^-3)
ln k2+ 4.39 s^-1 = 1.2x 10^5 J/mol / 8.3145 (1.5*10^-4 )

ln k2+ 4.39 s^-1 = 2.16

ln k2 = -2.23

k2 = 0.108 s-1

queen_honey_blossom answered 1 year ago

Next > < Previous

Related Solutions

A reaction has a rate constant of 1.19×10−2 /s at 400. K and 0.693 /s at...

A reaction has a rate constant of 1.19×10−2 /s at 400. K and 0.693 /s at 450. K. A) Determine the activation barrier for the reaction B) What is the value of the rate constant at 425 K

A reaction has a rate constant of 1.23 x 10 ^-2 /s at 400 K and...

A reaction has a rate constant of 1.23 x 10 ^-2 /s at 400 K and .688/s at 450K. What is the activation barrier for the reaction and what is the value of the rate constant at 425 K ?

The rate constant for a certain reaction is k = 1.90×10−3 s−1 . If the initial...

The rate constant for a certain reaction is k = 1.90×10−3 s−1 . If the initial reactant concentration was 0.850 M, what will the concentration be after 15.0 minutes? A zero-order reaction has a constant rate of 2.80×10−4 M/s. If after 75.0 seconds the concentration has dropped to 9.00×10−2 M, what was the initial concentration? A zero-order reaction has a constant rate of 2.80×10−4M/s. If after 75.0 seconds the concentration has dropped to 9.00×10−2M, what was the initial concentration?

The equilibrium constant for the reaction below is K = 0.36 at 400 K. If 1.5...

The equilibrium constant for the reaction below is K = 0.36 at 400 K. If 1.5 g of PCl5 was initially placed in a reaction vessel with a volume of 250 cm3, what is the molar concentration of each gas at equilibrium? What is Delta Gorxn for the reaction: PCl5 (g) à PCl3 (g) + Cl2 (g) - Please show all work.

The reaction below has an equilibrium constant K p =2.2× 10 6 at 298 K. 2...

The reaction below has an equilibrium constant K p =2.2× 10 6 at 298 K. 2 COF 2 (g)⇌ CO 2 (g)+ CF 4 (g) Part A Calculate K p for the reaction below. COF 2 (g)⇌ 1 2 CO 2 (g)+ 1 2 CF 4 (g) Part B Calculate K p for the reaction below. 2 3 COF 2 (g)⇌ 1 3 CO 2 (g)+ 1 3 CF 4 (g) Part C Calculate K p for the reaction below....

For a given reaction, the rate constant is k'= 2.0 * 10^-4 Lmol^-1s^-1 at T' =...

For a given reaction, the rate constant is k'= 2.0 * 10^-4 L*mol^-1*s^-1 at T' = 298K and k= 4.5 * 10^-3 L*mol^-1*s^-1 at T=345K Calculate the Arrhenius parameter A

1. The rate law for a given reaction is rate = k[NOBr]2. The rate constant is...

1. The rate law for a given reaction is rate = k[NOBr]2. The rate constant is 1.0 x 10-5 1/M∙s, and the initial concentration was 0.100 M. What is the first half-life of this reaction? A) 0.50 s B) 6.9 x 104 s C) 1.0 x 10-5 s D) 1.0 x 106 s E) None of these 2. The reaction SO2Cl2 SO2 + Cl2 is first order in SO2Cl2. If the concentration of SO2Cl2 after 198 s is 1.47 x...

Part A A certain first-order reaction has a rate constant of 2.30×10−2 s−1 at 25 ∘C....

Part A A certain first-order reaction has a rate constant of 2.30×10−2 s−1 at 25 ∘C. What is the value of k at 63 ∘C if Ea = 74.0 kJ/mol ? Part B Another first-order reaction also has a rate constant of 2.30×10−2 s−1 at 25 ∘C . What is the value of k at 63 ∘C if Ea = 128 kJ/mol ?

A reaction has a rate constant of 1.28×10−4 s−1 at 25 ∘C and 0.233 s−1 at...

A reaction has a rate constant of 1.28×10−4 s−1 at 25 ∘C and 0.233 s−1 at 75 ∘C. What is the value of the rate constant at 15 ∘C?

A reaction has a rate constant of 1.22×10−4 s−1 at 28 ∘C and 0.229 s−1 at...

A reaction has a rate constant of 1.22×10−4 s−1 at 28 ∘C and 0.229 s−1 at 79 ∘C . What is the value of the rate constant at 16 ∘C ?

Subjects