Question

The activation energy for the gas phase decomposition of 2,3-dichloropropane is 230 kJ.

[CH₃CHClCH₂Cl rightarrow CH₃CH=CHCl + HCl]

The rate constant at 714 K is 0.000973/s. The rate constant will be _____ /s at (?) K.

a) 0.001242
b) 0.002456
c) 0.003721
d) 0.004789

The activation energy for the gas phase decomposition of difluoroperoxide is 72.4 kJ.

[F₂O₂F₂ rightarrow O₂]

The rate constant at 230.0 K is 0.000420/s. The rate constant will be ______ /s at (?) K.

a) 0.000528
b) 0.000612
c) 0.000718
d) 0.000825

Answer 1

To find the rate constant at a given temperature, use the Arrhenius equation. Rearrange the equation to find the rate constant at an unknown temperature using the provided data. Plug in the values for K1, T1, Ea, and R to solve for K2.

Step-by-step explanation:

To find the rate constant at a given temperature, we can use the Arrhenius equation:

K = A * exp(-Ea/RT)

where K is the rate constant, A is the pre-exponential factor or frequency factor, Ea is the activation energy, R is the gas constant (8.314 J/mol·K), and T is the temperature in Kelvin.

To find the rate constant at the unknown temperature, we need to rearrange the equation:

K2 = K1 * exp(-Ea/R * (1/T2 - 1/T1))

where K2 is the rate constant at the unknown temperature, K1 is the rate constant at the given temperature, Ea is the activation energy, R is the gas constant, T2 is the unknown temperature in Kelvin, and T1 is the given temperature in Kelvin.

Plugging in the values from the given question:

K1 = 0.000973/s, T1 = 714 K, Ea = 230 kJ/mol

K2 = ? , T2 = ?

K2 = 0.000973/s * exp(-230 kJ/mol / 8.314 J/mol·K * (1/T2 - 1/714 K))

Now we can solve for K2 by substituting the values of T2 into the equation.