Orders and rate constants

You will write functions for the method of initial rates. One finds the order in a reactant from two runs. One finds the rate constant from a run. One tells you whether a number can be the molecularity of an elementary step.

The idea. When only $[\text{A}]$ changes, $\dfrac{\text{rate}_2}{\text{rate}_1} = \left(\dfrac{[\text{A}]_2}{[\text{A}]_1}\right)^x$. So $x = \dfrac{\log(\text{rate}_2/\text{rate}_1)}{\log([\text{A}]_2/[\text{A}]_1)}$. The rate constant is $k = \dfrac{\text{rate}}{[\text{A}]^x[\text{B}]^y}$.

Your tasks.

1. Complete order(rate_a, rate_b, conc_a, conc_b) so that it returns the order in the reactant whose concentration changed.
2. Complete rate_constant(rate, concs, orders) so that it divides the rate by every concentration raised to its own order.
3. Complete possible_molecularity(m) so that it returns True only for the numbers an elementary step can have.