Question

For the gas-phase decomposition of chloroethane,

CH₃CH₂Cl→C2H₄+HCl

The rate constant has been determined at several temperatures. When ln k in s⁻¹ is plotted against the reciprocal of the Kelvin temperature, the resulting linear plot has a slope of -3.06 x 10⁴ K and a y-intercept of 33.6.

The activation energy for the gas phase decomposition of chloroethane is _____ kJ mol⁻¹

Answer 1

The activation energy for the gas phase decomposition of chloroethane is calculated to be 254.414 kJ/mol, using the provided slope from an Arrhenius plot.

Step-by-step explanation:

The student is asking for the determination of the activation energy for the gas-phase decomposition of chloroethane using the slope from an Arrhenius plot, where the natural logarithm (ln) of the rate constant (k) is plotted against the reciprocal of the absolute temperature in Kelvin (1/T). According to Arrhenius equation, the slope of this linear plot is equal to -Ea/R, where Ea is the activation energy and R is the universal gas constant (8.314 J/(mol·K)). Given that the slope is -3.06 x 10´ K, we calculate the activation energy by multiplying the slope by -R.

Ea = - slope x R

Ea = - (-3.06 x 10´ K) x (8.314 J/(mol·K))

Ea = 254414 J/mol

Ea = 254.414 kJ/mol

Therefore, the activation energy for the gas phase decomposition of chloroethane is 254.414 kJ/mol.