For the reaction A + B + C D The following data were obtained at constant temper

Question

For the reaction
A + B + C D
The following data were obtained at constant temperature:

1. What is the order with respect to each reactant? (Enter the order for A as Answer 1, that for B as Answer 2, and that for C as Answer 3. You must get all 3 correct.)

2. What is the value of the rate constant for the reaction at this temperature?

Trial Initial [A] (mol/L) Initial [B] (mol/L) Initial [C] (mol/L) Initial Rate (mol/L . s) 1 0.2790 0.1670 0.0334 1.190 2 0.5580 0.1670 0.0334 2.381 3 0.5580 0.3340 0.0334 9.524 4 0.2790 0.1670 0.0668 1.190

Explanation / Answer

Answer –

We are given, reaction – A + B + C -------> D

We assume rate law is ,Rate = k [A]x [B]y [C]z

The x,y and z are the order with respect to A, B and C

So,

Rate1 = k [A]1x [B]1y [C]1z

Rate2 = k [A]2x [B]2y [C]2z

Rate3 = k [A]3x [B]3y [C]3z

Rate4 = k [A]4x [B]4y [C]4z

Now we need to calculate order with respect to A means x, so we need to take ration Rate 2 by Rate 1

Rate2/ Rate1 = k [A]2x [B]2y [C]2z / k [A]1x [B]1y [C]1z

2.381 / 1.190 = (0.5580)x /(0.2790)x * (0.1670)y /(0.1670)y *(0.0334)z /(0.0334)z

   2 = (2)x

So, x = 1

Now we need to calculate z

Rate3/ Rat21 = k [A]3x [B]3y [C]3z / k [A]2x [B]2y [C]2z

9.524 / 2.381 = (0.5580)x /(0.5580)x * (0.3340)y /(0.1670)y *(0.0334)z /(0.0334)z

    4 = (2)y

So, y = 2

Now we need z calculate

Rate4/ Rate1 = k [A]4x [B]4y [C]4z / k [A]1x [B]1y [C]1z

1.190 / 1.190 = (0.2790) / (0.2790) * (0.1670)2 /(0.1670)2 *(0.0668)z /(0.0334)z

1 = (2)z

So, z = 0

So the order with respect to A is 1, for B it is 2 and for C it is 0. So rate of reaction depends on A and B.

So, rate law

Rate = k [A] [B]2

Now we need to put the values and calculate k

1.190 Ms-1 = k (0.2790)*(0.1670)2

k = 1.190 /0.00778

k = 153 M-2 s-1

Related Questions

Navigate

• Browse (All)
• Browse F
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.