For the reaction A + 2B + C ----> 2 D + E the following initial concentration and initial reaction rates are found:
[A]null (M) [B]null (M) [C]null (M)
0.150 0.150 0.150
0.275 0.150 0.150
0.275 0.564 0.150
0.150 0.314 0.253
0.193 0.314 0.217
initial rate wrt E (Ms^-1)
0.210
0.285
4.037
0.125
?????
a) find the exponents m n and p of the reactants A B and C
b)what is the overall order to reaction for this reaction?
c)find the rate constant k using experiment 3 including units.
d)find the rate of reaction wrt E for experiment 5
so far....i've attempted the questions but i'm stuck. here's what i have
rate=k[A]^n[B]^m[C]^p
rate 2/rate 1=
0.285/0.210=k(.275)n(.150)m(.150)p/
k(.150)(.150)(.150)
1.36 = (.275/.150)
1.36 = (1.83)^n
is this correct so far????
thanks in advance
Yes, you are on the right track so far. Let's go through each question step by step:
a) To find the exponents (m, n, and p) of the reactants A, B, and C, you need to compare the initial rates of the reaction when the concentrations of each reactant are changed while keeping the other concentrations constant.
In this case, you can compare the initial rates from experiments 1 and 2:
rate 2 / rate 1 = 0.285 / 0.210 = (0.275)^n
From your calculations, you found that 1.36 = (1.83)^n. To find the exponent 'n', you can take the logarithm of both sides:
log base 1.83 (1.36) = n
Using logarithm properties, you can rearrange the equation to solve for 'n'. Plug in the values into a calculator to get the result.
b) The overall order of the reaction is the sum of the exponents of the reactants. So, once you determine the values of 'm', 'n', and 'p', you can calculate the overall order.
c) To find the rate constant 'k' using experiment 3, you need to use the equation:
rate = k[A]^n[B]^m[C]^p
From experiment 3:
rate 3 = 4.037 Ms^-1
[A]null = 0.275 M
[B]null = 0.564 M
[C]null = 0.150 M
Substitute these values into the equation and solve for 'k'. Make sure to include the appropriate units.
d) To find the rate of reaction with respect to E for experiment 5, you need to use the equation:
rate = k[A]^n[B]^m[C]^p[E]
Since the exponents 'm', 'n', and 'p' are still unknown, you can't directly calculate the rate. What you can do is use the data from experiment 5 and the calculated rate constant 'k' from experiment 3 to find the rate.
Experiment 5:
[A]null = 0.193 M
[B]null = 0.314 M
[C]null = 0.217 M
Substitute these values into the equation along with the 'k' value calculated in part c, and solve for the rate. Make sure to include the appropriate units.
I hope this helps! Let me know if you have any further questions.