Question

The decomposition of dimethyl ether leads to the formation of CH₄, H₂ and CO and the reaction rate is given by Rate = k [CH₃OCH₃]^3/2. The rate of reaction is followed by increase in pressure in a closed vessel, so the rate can also be expressed in terms of the partial pressure of dimethyl ether, i.e., Rate = `k(P_(CH_3OCH_3))^(3/2)`.

If the pressure is measured in bar and time in minutes, then what are the units of rate and rate constants?

Answer 1

If pressure is measured in bar and time in minutes, then

Unit of rate = bar min⁻¹

Rate = `k(P_(CH_3OCH_3))^(3/2)`

k = `"Rate"/(P_(CH_3OCH_3))^(3/2)`

Therefore, unit of rate constants (k) = `("bar min"^-1)/"bar"^(3/2)`

= `"bar"^(-1/2)  "min"^(-1)`