[makomankanshoku2004]

An Investigation is carried out in which evidence is collected for the hypothetical reaction: W + 2X + 2Y —------------>  Z  (W, X, and Y could be either elements or compounds, but Z is a compound.)

Table 1: Observation on the Rate of Reaction
Trial #   Initial [W] mol/L     Initial [X] mol/l    Initial [Y] mol/L  Rate of Production of Z   
                                                                                                        (mmol/L.s)
1             0.10                        0.10                      0.10                     12
2             0.20                        0.10                      0.10                     12
3             0.10                        0.20                      0.10                     24
4             0.10                        0.10                      0. 20                    48

– a) State the General rate law equation for the above reaction. 2 Marks
Hint: Use m, n, and O as the Exponents.
– b) Calculate the value for the exponents of the rate law equation and state the Specific rate law equation, show all your calculations. 8 Marks
– c) What is the overall order of reaction? 1 Mark
– d) determine the value and unit of “k” by using the Trial # 1 ONLY. 4 Marks

Application Part: 6 Marks
– a) Write the equation for the rate determining Step?
Hint: Use the Specific Rate Law Equation. 2 Marks
– b) Write a possible reaction mecanism. Also state the intermediate reactions. 4 Marks
Hint: Use the balanced chemical equation.

I did question A the answer is R= k * [W]m * [X] of 2n * [Y] 20. K is rate of constant  m is order of reaction with respect to reactant. W 2n= order of reaction with respect to reactant.       

[makomankanshoku2004]

can someone please explain what to do next like for question b im stuck i dont know what to do what the question is asking for someone please help

[makomankanshoku2004]

i did question a i did the work for question a can someone please guide me for question b

[sjb]

I did question A the answer is R= k * [W]m * [X] of 2n * [Y] 20. K is rate of constant  m is order of reaction with respect to reactant. W 2n= order of reaction with respect to reactant.       

Not quite. How does experiment 1 differ from experiment 2?

[makomankanshoku2004]

 Initial [W] mol/L  is 10 more for the second trial.

[Orcio_87]

Table 1: Observation on the Rate of Reaction
Trial #   Initial [W] mol/L     Initial [X] mol/l    Initial [Y] mol/L  Rate of Production of Z   
                                                                                                        (mmol/L.s)
1             0.10                        0.10                      0.10                     12
2             0.20                        0.10                      0.10                     12
3             0.10                        0.20                      0.10                     24
4             0.10                        0.10                      0. 20                    48

Initial [W] mol/L  is 10 more for the second trial.

I think that 0,2 / 0,1 = 2, so it is 2, not 10 times bigger.

[makomankanshoku2004]

alright i should correct that what to do next?

[makomankanshoku2004]

also quick q, is that the exponent 0.2? Is that the only exponent or is there more.

[Orcio_87]

Next..

Change of concentration of W in 1 and 2 trial did not changed reaction rate.

But - change of concentration of X and Y in trials 3 and 4 changed it 2 - 3 times bigger.

This can be used to write m, n, o paramaters in reaction rate equation.

[Orcio_87]

also quick q, is that the exponent 0.2? Is that the only exponent or is there more.

Exponents are m, n and o.

[makomankanshoku2004]

alrighty

[makomankanshoku2004]

quick q, how does one find the exponents m n and o the values from the provided data?

[Orcio_87]

One write down the equation for reaction rate and then compare it to the data.

Concentration increased two times, but overall reaction rate did not changed.

Concentration increased two times, but overall reaction rate increased 2 or 4 times.

This means that values of m, n and o are restricted to some numbers.

[Orcio_87]

You can also calculate the logarithm (m, n and o) if you're not sure.

[natalie5933]

It is simple. The rate law will be rate = k [W]^0 [X]^1 [Y]^2.

Ig u see the observation table when u r keeping conc of X and Y constant and doubling conc of W. The rate is unchanged that means the rate isn't affected by the concentration of W so the order of the reaction with respect to W is 0. Next if u r keeping the conc of W and Y constant and doubling the conc of X the rate is doubling thus the order with respect to X is 1. Similarly, when the conc of Y is doubled keeping other conc same, the rate inc 4 times indicating 2nd order with respect to Y.

and the overall order of the rxn will be 3.