OK.

Do this…

Scroll down for solution

–

–

–

–

–

–

–

–

–

–

–

–

–

–

–

–

–

–

Experiment 2 and 3, [E] & [G] are constant. [F] doubles and rate doubles.

Because (reagent conc. Increase)^{order} = rate increase, 2^{y}=2 so order w.r.t. **F** must be 1.

Experiment 3 and 4, [E] increases by almost 12 times, [F] increases by a factor of 4 and [G] increases by 10 times. Rate increased by a factor of 575

So 12^{x} x 4^{1} x 10^{z} = 575

Divide by 4 gives 12^{x} x 10^{z} = 144. Given that the orders w.r.t. the reactants must be 0,1 or 2. Then we have these possibilities….

x=0. z=0

x=1, z=0

x=2, z=0

x=0. z=1

x=1, z=1

x=2, z=1

x=0. z=2

x=1, z=2

x=2, z=2

Clearly the only way 12^{x} x 10^{z} can equal (via whole number power terms) is if x=2 and z=0 {note: 144 is 12^{2} with no other contribution from the “ 10^{z} “ term}

Hence order w.r.t.: F=1, E=2 and G=0

Rate equation = k[F]^{1}[E]^{2}[G]^{0} or simply rate = k[F]^{1}[E]^{2}

We could have done this via experiment 1 and two (and in fact would have been easier as the [F] is const. From expt. 1 to 2, [E] increases by a factor of (almost)6 times. [F] is constant, [G] increases by a factor of 5 times and the rate increases by a factor of 36. So, 6^{x} x 5^{z} = 36. 36 is 6^{2} alone, so again we deduce x=2 and z=0